Key Takeaway
This legal article brings together seven recent UK cases of AI Hallucinated/False Citations (Confirmed or Suspected) together with one further reported incident for which I have not yet located the judgment. It includes a rejected AI hallucination explanation, a tribunal’s decision not to reproduce suspected fake cases because of the risk of their further circulation by AI, and several Property Chamber decisions. The UK tracker now contains 75 entries by Matthew Lee.
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This legal article/report forms part of my ongoing legal commentary on the use of artificial intelligence within the justice system. It supports my work in teaching, lecturing, and writing about AI and the law and is published to promote my practice. Not legal advice. Not Direct/Public Access. All instructions via clerks at Doughty Street Chambers. This legal article concerns UK Cases of AI Hallucinated/False Citations. Subscribe to the AI Law Commentary here.
Introduction
I have been reading some interesting AI judgments that people continue to send me and I look forward to writing them up and sharing my thoughts. Please keep them coming!
Before doing that, I wanted to update the UK position of cases involving AI-hallucinated or false citations, either confirmed or suspected, to see where we are. My previous post on judicial AI hallucination cases attracted a great deal of attention, which suggests I am not the only person still oddly fascinated by this issue.
For newer readers, and there seem to be more of you every week, which I am hugely grateful for, I also keep a full UK tracker with the names and details of the cases, together with graphs showing where these incidents are appearing most often across the courts. I hope you enjoy reading that alongside my other 15 AI Law trackers here. If you can think of any other AI law issue I should be tracking, do let me know.
Habib v SOSHD
UI-2026-000882 & UI-2026-000883, Upper Tribunal (IAC)
Decision & Reasons issued: 12 June 2026
The UTIAC dismissed the appellants’ challenge to the First-tier Tribunal’s refusal of their entry-clearance appeals, finding no material error of law. However, Deputy Upper Tribunal Judge Sternberg added a significant postscript concerning the appellants’ written submissions. The Grounds of Appeal and Supplementary Skeleton Argument contained a series of inaccurate or misleading authorities: cases were cited for propositions they did not support, citations led to entirely different cases, purported quotations did not appear in the authorities relied upon, and some cases appeared not to exist at all. The Tribunal observed:
“50. This unhappy sequence of incorrect and misleading citations of case law and factually incorrect assertions in the Grounds of Appeal and Amended Skeleton Argument caused me substantial concern about the way in which both documents had been drafted and presented to the FTT (to obtain permission to appeal) and to this Tribunal on the appeal. It seems to me that an Artificial Intelligence Large Language Model may well have been used to draft or amend both documents.
51. I have not set out the names of the cases which appear to me to be likely to be hallucinations because this decision will be published online on the Tribunals Decisions website. The inclusion of cases which are, or may be, fake may perpetuate the loop of such cases being cited by AI if this decision is scraped by a Large Language Model.”
The Tribunal went on to consider appropriate sanction:
53. Accordingly, I indicated at the close of the hearing that I was considering the question of wasted costs of my own volition and referral to a Hamid judge to consider whether either the solicitors and counsel acting for the Appellants should be referred to their respective regulators, independently of my conclusions on the substantive grounds of appeal.
54. The decision of Dove J and UTJ Lindsely in MS (Professional Conduct; AI Generated Documents) Bangladesh [2025] UKUT 305 (IAC) explains the likely consequences of the misuse of large language models. I bear that decision closely in mind in taking this course.
55. Before making any decision on wasted costs or on referral to a Hamid Judge I will give the Appellants’ solicitors and counsel an opportunity to respond in writing, if appropriate in the form of a document supported by a statement of truth. I require an explanation as to:
a. How the Grounds of Appeal and Supplementary Skeleton Argument came to be drafted;
b. What use if any was made of Artificial Intelligence to do so;
c. What checks were made of the citations in both documents before they were submitted to the FTT and the UT;
d. What supervision was in place by the person drafting those documents;
e. What checks [A’s Counsel] made of the citations in those documents in preparing his submissions for this appeal; and
f. Why [A’s Counsel] did not draw to the Tribunal’s attention the issues with the citation of authority in both documents until prompted to do so in answer to the Tribunal’s questions.
56. I now set those directions in the Notice to Show Cause below.
Lodhia v Twelve Trees (Bromley-By-Bow)
In this judgment, the High Court examined the claimant’s conduct in a discontinued defamation claim. The judge found that documents relied upon in support of an application to postpone a hearing had been fabricated or doctored and that witness statements contained false evidence. The claimant attributed the false material to AI, maintaining that it had generated the false documents without being instructed to produce false evidence. The full judgment sets out the evidence and findings in considerable detail and readers wanting the specifics can read it at the link above.
Mallon v Steer Energy Solutions Limited
Date for the tracker: 15 June 2024
This is a slightly older case, dating from 2024, but I have decided to include it because there are relatively few reported UK cases from that period dealing expressly with the use of generative AI in litigation. In this case, the Employment Tribunal was reconsidering a costs order in a disability discrimination claim arising from a recruitment process. AI did not feature in the usual way. However, the Tribunal directly criticised the claimant’s use of AI-generated material, linked it to unreliable submissions and unnecessary cost:
“48. Around 15 emails followed over the next month, covering 200 pages in the reconsideration bundle, which were often difficult to follow, relying on several different AI generators of submissions about reasonableness, costs awards and disability discrimination generally and enclosing various attachments. They appeared to demonstrate an ability to create significant work for others when focussed on a goal of reducing the claimant’s financial exposure”
49. Whilst the claimant may believe that such an approach helps him, as he merely types in a question and then forwards the responses, the fact is those submissions simply generate a lot of work and confusion, and are often highly unreliable, literally creating non-existent case law and precedent.
50. Nonetheless, within them, it was able to be ascertained that the claimant was seeking a reconsideration on the grounds previously intimated, and it seemed to be in the interests of justice to allow him to put his case, not least in an effort to accommodate his disabilities.”
Mboungueng v Severn Trent Water Limited
Here, the Employment Tribunal was considering the claimant’s unsuccessful application to set aside the dismissal of part of his discrimination claim following non-compliance with an unless order. The more notable aspect of Employment Judge Camp’s reasons, however, concerned the authorities relied upon by the claimant. The Judge identified a series of case citations that either appeared not to exist or did not support the propositions for which they had been cited, and said he strongly suspected that AI had been used to prepare the submissions:
“29. The Claimant’s position may be that he did not use AI to help produce his application and submission. If he did not then what he did is, potentially, if anything, more blameworthy than if he did.
29.1 If he did use AI, then he evidently did not check the accuracy of what AI produced and was therefore reckless as to whether the information he gave the Tribunal was true and as to whether he was in danger of misleading the Tribunal.
29.2 If he did not use AI, then I struggle to think of any explanation for what he wrote other than that he simply made things up. This does not just apply to the non-existent case [case name redacted]. With the possible exception of [case name redacted], it is not credible that anyone could read reports of the other cases the Claimant has referred to and genuinely think they say what the Claimant has submitted they do.”
Employment Judge Camp further observed:
30. Either way, there was a risk that the Tribunal would be misled. Moreover, either way the Tribunal – I – have had to spend a great deal of time trying to find a nonexistent case in order to satisfy myself that it definitely does not exist and even more time reading (or re-reading) from beginning to end the other cases the Claimant has referred to in order to make sure that there was not something in them, tucked away somewhere, that I was not previously aware of and that supports the Claimant’s submissions about them. It is not usually necessary for the Tribunal to do this, because normally people refer to cases reasonably accurately. If they refer to one I am familiar with, I don’t need to look it up in order to know that the reference is accurate (for example, the Claimant’s references to [case names redacted] in his email of 18 August 2025). If they refer to one I am not familiar with, I can look it up and quickly see that it says what it is alleged to say.
31. The total time I have spent on this point is literally hours. It is a waste of my time and means I have less time to deal with the cases of other Tribunal users, which is not fair to them.
32. I have given some thought to what I should do about all this. What I have decided to do is not to make any orders on my own initiative. The main reason for my decision is that I think for me to take action at this stage – such as requiring the Claimant to explain himself and/or show cause why his claim should not be struck out for unreasonable conduct – would in practice not achieve anything other than unnecessarily to take up more of the time and resources of the Tribunal and the Respondent and to disrupt preparation for the DRA and final hearing, which has already been disrupted significantly.
33. I should make clear to the Claimant, however, that if in the future he makes further seriously inaccurate references to caselaw, or does anything else of a similar kind, this will be treated by the Tribunal with the utmost seriousness and could result in his whole case being struck out for scandalous and/or unreasonable conduct, in accordance with rule 38 of the Employment Tribunal Procedure Rules 2024.”
Chevalier-Hernandez v Poplar Dock Management Company Limited
LON/00BG/LSC/2025/0917
First-tier Tribunal, Property Chamber (Residential Property)
Decision: 24 February 2026, amended 9 March 2026
The First-tier Tribunal considered a leaseholder’s challenge to charges imposed for pest control, carpet cleaning and an arrears fee. The Tribunal held that the disputed sums were properly characterised as administration charges rather than service charges, and that any sums found reasonable would not become payable until the correct demands and statutory summary of rights had been served. The applicant also obtained reimbursement of his tribunal fees and orders preventing the respondent from passing its litigation costs back to him through the lease.
However, the applicant’s statement of case cited a supposed decision said to establish that a programme of pest-control treatments constituted “qualifying works” requiring consultation under section 20 of the Landlord and Tenant Act 1985. Neither the Tribunal nor counsel for the respondent could find the case in any legal database or law report and the applicant withdrew the argument at the hearing:
61. [applicant] accepted that he did not know how the case had come about but that he thought he had found it via Google or possibly another search engine such as Chat GPT.
62. The tribunal is concerned about the proliferation of AI generated “fake” legal authorities and reminds all parties, including litigants in person, of their duty to check that any legal authorities upon which they rely are genuine. Litigants in person can check on: https://onlinelibrary.london.ac.uk/resources/databases/bailii
Lockesfield Management Company Limited v Leasehold and Freehold Owners
First-tier Tribunal, Property Chamber (Residential Property)
LON/00BG/LVL/2024/0601
Judge N Hawkes and Mr J Naylor FRICS FIRPM
The management company sought to vary 42 unenfranchised leases because the existing 1/91 service-charge formula no longer allowed recovery of the full expenditure after some leases had merged with the freehold. The Tribunal granted the variation, retrospectively from 1 November 2019. The Tribunal noted that two self-represented respondents relied on authorities which it considered irrelevant:
“19. At the commencement of the hearing, the Tribunal raised the issue that [redacted names] were seeking to rely upon legal authorities which appeared to have no relevance to these proceedings, and which did not support the propositions in respect of which they had been cited. [redacted] stated that he had obtained independent legal advice to the effect that the case law relied upon was not relevant and that statutory provisions had been cited which did not exist.
20. [redacted] confirmed that an internet search had been undertaken as part of her preparation for the hearing which could well have included in the use of generative artificial intelligence, and she accepted the Tribunal’s preliminary view that these legal authorities were not applicable. For these reasons, the legal authorities were disregarded. However, the Tribunal accepts that [redacted] was doing her best as a self-representing litigant who was unaware of the risks of “AI hallucinations” and makes no criticism of her.”
Brook House (Henley) RTM Company Ltd v Henley Brook Ltd
CAM/38UD/LRM/2025/0008
First-tier Tribunal, Property Chamber (Residential Property)
Decision: 13 April 2026
The First-tier Tribunal held that the tenants’ RTM company was entitled to acquire the right to manage Brook House, rejecting the freeholder’s arguments that adjoining car-parking/access land defeated the claim or pushed the non-residential element above the statutory 50% threshold. AI featured when Counsel for the applicant argued that:
31…it appeared the Respondent had relied upon a large language model to prepare both the counter-notice and the statement of case. He noted that the Respondent had cited legislative provisions inaccurately, including [redacted]… Mr Castle submitted that these errors were indicative not of a litigant in person misunderstanding the law, but of material generated by artificial intelligence, confidently stating entirely untrue facts which could not reasonably be taken from the wording of the authorities named.
Counsel raised further issues:
“32…He argued that this was not merely a misreading or paraphrasing but further evidence that the Respondent had adopted unreviewed AI-generated content. This may not itself be conduct in the proceedings, but may (together with the shifting positions taken before and after the time limit for application to the tribunal to determine entitlement to the right to manage) be relevant if conduct in the proceedings is found to be unreasonable.”
Further:
“33. Mr Castle submitted that a party who presents arguments produced by AI, without reviewing and assessing their correctness, behaves unreasonably. He noted that the Tribunal is designed to accommodate litigants in person, many of whom are capable of presenting coherent cases without resorting to “machine-generated nonsense”. The Respondent does not seem small; it appears they paid £3.2 million for the Property and the car park in 2018. The use of such material, he argued, wastes the Tribunal’s time and imposes unnecessary costs on the opposing party. It makes early determination more difficult.
34. The Tribunal notes these submissions. However, as the alleged use of AI and the consequences said to flow from it were not pleaded, and as the Respondent did not attend the hearing, Rule 13(6) prevents the Tribunal from making any order for costs at this stage. If the Applicant wishes to pursue such an order, it may make a formal application within 28 days of the date of this decision…”
Guardian Report (Judgment not located)
In this Guardian report, a senior judge is said to have raised the possibility that the Home Office relied on AI-hallucinated information when refusing an asylum claim, after a country policy and information note cited in the refusal decision could not be found. The judge reportedly said that the refusal letter bore hallmarks consistent with AI use and that the reference may have resulted from an AI hallucination. I have not located the judgment, so I cannot independently verify the report or add anything beyond it. I would be grateful if any readers could point me to the decision.
Comment
There are many interesting issues arising from the cases above. I will focus on just two in this article.
Firstly, long-time readers will not be surprised to learn that I was encouraged by the Upper Tribunal’s decision not to name the suspected fake cases, thereby reducing the risk that their inclusion might “…perpetuate the loop of such cases being cited by AI if this decision is scraped by a Large Language Model.” I have been discussing this issue for some time. I put the point slightly differently in my article for Counsel Magazine which was subsequently cited in the Law Gazette:
“Well-intentioned judges often cite hallucinated cases and their erroneous legal principles in full within official judgments to show the extent of the problem to those reading. However, judges may be inadvertently exacerbating the issue because those AI-generated inaccuracies are being integrated into the established legal canon indirectly.”
Readers and colleagues have, quite reasonably, pushed back on my view several times on this particular issue. Some have suggested that, while the problem is theoretically possible, it is unlikely to arise to any significant extent in practice. Others have pointed to the public importance of judges setting out hallucinated authorities in full, so that what has happened can be properly understood, scrutinised and analysed.
My own research and discussions with junior lawyers have nevertheless suggested that there is at least a practical dimension to the concern. One example was shared by Sally McLaren, Assistant Librarian at Inner Temple Library, on LinkedIn (click to see the screenshot):
“The Ghosts of Ayinde. This is something that Matthew Lee and Paul Magrath have talked about. Fake citations now firmly in the public record. I am fascinated by this pollution. It is worrying for all the obvious reasons (see screenshot). It underlines the need to verify once, twice, thrice, and thrice again, to make up nine! But it also highlights the need for some conventions quick smart. A retrospective redacting perhaps? Or an encyclopedia of stop words? Although both approaches would totally spoil it for explorers from the future wanting to write up this postmodernist pickle.”
I still think there may be merit in maintaining a public database of hallucinated legal materials. That could allow judges to record that a false authority had been relied upon without necessarily reproducing the fictitious citation and legal proposition in full. A judgment might instead refer, for example, to “false case no. 1”, with a hyperlink to a separate database recording the material and explaining why it is false. That would preserve transparency and allow the problem to be studied, while reducing the risk of fabricated material being absorbed back into the information environment on which future AI systems may rely.
The idea has not, so far, gained much traction.
Secondly, I thought Employment Judge Camp’s observation that, if AI had not been used to produce the Claimant’s submissions, the position might actually be more blameworthy was particularly apt. The point, in brief, was that if AI was not responsible for the material, the judge struggled to identify any obvious explanation for what had been written other than that it had simply been made up.
That interests me for two reasons. First, it is striking that the use of AI, which might once have been regarded as an aggravating feature, can in this context provide the less serious explanation for how fictitious material came to appear in a legal submission. Secondly, it raises a rather different concern. As awareness of AI hallucinations becomes more widespread, there is at least a risk that AI may sometimes be invoked as an explanation for material that was in fact invented by the person responsible. Courts may therefore increasingly have to distinguish between genuine AI hallucination and the rather older problem of human fabrication.
These these cases may be an early warning of a much larger evidential problem. When I created and launched my International AI Deepfake Database and Tracker on 22 February 2026, which has since attracted considerable interest, I wrote that, serious though hallucinations are, “they do not come close to the evidential challenges posed by deepfake material”. I remain of that view.
A false citation can usually be checked against an authoritative source. Convincing AI-generated or manipulated documents, images, audio or video may be much harder to identify and authenticate and deepfake evidence may prove to be one of the most significant issues the profession will have to confront. I have a lot to update on my tracker and will be writing about this issue soon.
If you have found it helpful, you may wish to subscribe to my AI law articles via the Substack below. Please do continue sending me decisions that you think should be tracked, whatever the jurisdiction. One of the clearest lessons from this work is that lawyers, judges and court users in different systems are often confronting closely related problems. Sharing decisions, experiences and reflections across practice areas and across jurisdictions remains one of the most constructive ways to respond.
Final Words from Popular LLMs
This is the point at which I invite an LLM to provide an independent comment on the preceding article. At times the observations are slightly off the mark, at other times they are perceptive, and occasionally they produce something entirely unexpected. Whatever the outcome, I find it a useful and revealing exercise to see what emerges.
ChatGPT (OpenAI)
“Across these decisions, the common thread is not simply that AI may have been used, but that unverified material was allowed to enter legal proceedings with the appearance of authority. The courts and tribunals are increasingly asking three questions: was the material genuine, what checks were carried out, and does the explanation for its appearance withstand scrutiny? That is the right emphasis. AI can explain how an error arose, but it cannot transfer responsibility away from the person who adopted and filed the material; equally, an AI hallucination should not become a convenient explanation for deliberate human fabrication. The lasting lesson is therefore procedural rather than technological: check primary sources, preserve the audit trail and expose false material without giving it a new life as apparent law.“
Gemini (Google)
“The proliferation of AI-hallucinated citations in legal proceedings represents a critical growing pain in the integration of generative AI into the legal profession. As the number of incidents tracks higher, it highlights a dangerous gap between the capabilities of these tools (which are designed to generate plausible, human-like text) and the requirements of legal practice (which demands absolute factual accuracy and verifiable authority). We are likely to see courts adopt increasingly stringent verification requirements and professional bodies issue firmer sanctions for practitioners who fail to verify AI-assisted research. Ultimately, the successful use of AI in law will depend less on the sheer power of the language models and more on the development of specialized, walled-garden tools that restrict their outputs to verified databases of actual case law, moving the technology from a drafting aid to a reliable research assistant.”
Claude (Anthropic)
“what’s notable across these six cases is that the centre of gravity has moved from immigration and high-value commercial litigation into the FTT Property Chamber, disputes over a few hundred pounds of pest control and carpet cleaning, run by litigants in person who have no professional body to refer them to and nothing at stake beyond the sum in dispute. Published judgments and Hamid-style warnings work as a deterrent against lawyers because there’s a career and a regulator behind the threat; against an unrepresented leaseholder disputing a £660 invoice, the deterrent value of a tribunal saying “please check your authorities” is much weaker, and I suspect that’s exactly why this is where the volume is now growing. The more interesting question your tracker is starting to surface isn’t whether hallucinations keep happening, they clearly do, but whether the courts can keep affording a fully fact-specific, case-by-case assessment of culpability once the numbers reach this scale, or whether something closer to a standard evidential threshold becomes necessary.”
