Guide
AI hallucination court cases: what the record shows
Last updated: 20 October 2026. Maintained by LIA (Legal Intel AI). We list only decisions we could trace to a judgment or a reputable report, and we link the source. This is not legal advice.
The count
The most complete public record is the AI Hallucination Cases database kept by Damien Charlotin (HEC Paris). As of its 19 October 2026 update it listed 2,202 decisions. Its categories at that date:
- Fabricated material: 1,806
- Misrepresented material: 933
- False quotes: 587
- Outdated advice: 36
A decision can carry more than one category. By party, the largest groups are self-represented litigants (1,267) and lawyers (872). Judges (32) and experts (17) also appear. The database includes only decisions where a court found, or clearly implied, reliance on hallucinated material. The true number of fake citations filed is higher, because many are never caught.
Source: https://www.damiencharlotin.com/hallucinations/
Australia
| Decision | Date | What happened | Source |
|---|---|---|---|
| Handa & Mallick [2024] FedCFamC2F 957 | 19 Jul 2024 | Family law property matter. A solicitor appearing as agent handed up a list of four authorities prepared with AI-assisted legal software; neither the judge nor her associates could locate them. The hearing was adjourned and the solicitor was given time to show cause why he should not be referred to the Victorian Legal Services Board and Commissioner. | Judgment (Judge A Humphreys); named in Pasuengos (No 2) at [17] among the Court's AI judgments |
| Dayal [2024] FedCFamC2F 1166; (2024) 386 FLR 359 | Aug 2024 | The follow-up to Handa & Mallick: the practitioner was referred to the Victorian Legal Services Board and Commissioner. | Cited in Pasuengos (No 2) at [17]-[18], [28] |
| Valu v Minister for Immigration and Multicultural Affairs (No 2) [2025] FedCFamC2G 95; (2025) 386 FLR 365 | 31 Jan 2025 | Submissions prepared with ChatGPT cited non-existent cases and quotations attributed to the tribunal. Judge Skaros referred the legal representative to the Office of the NSW Legal Services Commissioner. | Judgment; cited in Pasuengos (No 2) at [17]-[18], [24] |
| Murray on behalf of the Wamba Wemba Native Title Claim Group v State of Victoria [2025] FCA 731 | 2025 | Federal Court explained the risks of reliance on AI at [12]. | Cited in Pasuengos (No 2) at [18] |
| JNE24 v Minister for Immigration and Citizenship [2025] FedCFamC2G 1314 | 2025 | Court set out the dangers of hallucinated cases; referral to regulator. "It is not the utilisation of AI... but rather the placing before the Court of false authorities or evidence." | Quoted in Pasuengos (No 2) at [19]-[20] |
| Re Walker [2025] VSC 714 | 2025 | Public reprimand; Moore J on the "emerging ubiquity of AI". | Cited in Pasuengos (No 2) at [17]-[18] |
| Pasuengos v Minister for Immigration and Citizenship (No 2) [2026] FedCFamC2G 96 | 3 Feb 2026 | Three non-existent authorities in submissions. Judge Gerrard referred the junior lawyer and the principal solicitor to the Legal Profession Conduct Commissioner (SA), without naming them. | Judgment |
| Dey v Minister for Immigration and Citizenship (No 2) [2026] FedCFamC2G 1799 | 14 Sep 2026 | The applicant's solicitor admitted that 11 authorities across his submissions did not exist. Judge Bingham ordered him personally to pay A$9,600 of the Minister's costs and named him as a public reprimand, rather than referring him to the regulator. | Benchmark (25 Sep 2026), Lawyers Weekly and Australasian Lawyer reports of the judgment |
Court guidance: Federal Court of Australia, Generative Artificial Intelligence Practice Note (GPN-AI), 16 April 2026. https://www.fedcourt.gov.au/law-and-practice/practice-documents/notice-to-profession/16-april-2026
United Kingdom
| Decision | Date | What happened | Source |
|---|---|---|---|
| Ayinde v London Borough of Haringey [2025] EWHC 1383 (Admin) | 2025 | Divisional Court on the risks of reckless reliance on AI, including possible contempt. | Cited in Pasuengos (No 2) at [18] |
United States
| Decision | Date | What happened | Source |
|---|---|---|---|
| Mata v Avianca, Inc. (S.D.N.Y.) | 22 Jun 2023 | Six fabricated cases from ChatGPT. Judge Castel imposed a $5,000 penalty on a firm and two lawyers. The first widely reported case. | Widely reported, incl. Massachusetts Lawyers Weekly, 13 Oct 2026 |
| Withers v City of Aberdeen, No. 1:24-cv-218 (N.D. Miss.) | 8 Jun 2026 | Both sides filed hallucinated citations. Trial cancelled; two pro hac vice admissions revoked and two-year bar from the district; fines of $2,500 and $3,500 for those two and $1,000 each for the two local counsel, who were disqualified; all four referred for discipline. Judge Aycock called one explanation "insufficient and incredulous". | Sanctions order, Dkt 123 (CourtListener); Bloomberg Law, 9 Jun 2026 |
| LeDoux v Outliers Inc, No. 3:24-cv-05808 (W.D. Wash.) | Jul-Aug 2026 | Counsel sanctioned under Rule 11 for dozens of inaccurate citations across at least five filings (Dkt 265, 24 Jul 2026, 2026 WL 2137370). The same AI-generated citation table had been given to both experts as an appendix, and neither caught the errors before signing. In August Judge Cartwright held that the hallucinated citations undermined one expert's entire report, which was not reliable under Daubert (Dkt 269, 18 Aug 2026, 2026 WL 2408808). | Orders Dkt 265 and Dkt 269 |
| In re Valsartan, Losartan, and Irbesartan Products Liability Litigation, MDL No. 2875 (D.N.J.) | 3 Sep 2025 | Special Master Thomas I. Vanaskie (Ret.) declined to exclude an expert, Dr William Sawyer, whose report contained citation errors, finding exclusion too severe, while saying costs and cross-examination on the errors were "perhaps" warranted. | Special Master Order, Dkt 3167 (CourtListener) |
| Couvrette v Wisnovsky, No. 1:21-cv-00157-CL (D. Or.) | Dec 2025 - Mar 2026 | Three summary-judgment briefs cited 15 non-existent cases and fabricated quotations attributed to eight real authorities. Magistrate Judge Clarke struck the briefs, imposed a $15,500 sanction on lead counsel and dismissed the claims with prejudice (ECF 215, 12 Dec 2025). In March 2026 he found the defendants' fees of $94,704.38 reasonable, split 85% to lead counsel and 15% to local counsel (ECF 225). | Opinion and Order ECF 215; Order ECF 225 |
| Aguilar v The Crawford Group, Inc. (D. Mass.) | Oct 2026 | Judge Angel Kelley revoked a California lawyer's pro hac vice status and ordered fees and costs of up to $10,000 after errors in about half the citations of a brief he said was prepared with AI-assisted research, with further errors in later briefs. Local counsel was not sanctioned but was reminded of the duty to supervise. | Massachusetts Lawyers Weekly, 13 Oct 2026 (Lawyers Weekly No. 02-493-26) |
| Kid International, LLC v City National Bank of Florida, No. 4D2025-2599 (Fla. 4th DCA) | 7 Oct 2026 | The court affirmed summary judgment, then granted the bank's sanctions motion: the initial brief cited a non-existent case seven times, with an invented quotation, and misquoted real cases. Counsel admitted his firm had used generative AI. Appellate fees were awarded against the appellants and counsel jointly and severally, the amount to be set by the trial court. | Opinion (flcourts.gov) |
What the decisions have in common
- Courts do not sanction the use of AI. They sanction filing material nobody checked.
- Supervision is part of the duty. Local counsel and principals who signed without checking have been disqualified, fined or referred.
- The invented case is the easy catch. False quotes and misrepresented holdings inside real cases are a large share of the record, and a citation check alone does not find them.
- Experts are in scope. In LeDoux, an unchecked citation table undermined an entire expert report.
A pre-filing check (any tool)
- Open every authority cited. Confirm it exists and says what it is cited for.
- Check every quotation against the paragraph it comes from.
- Confirm which pages of the evidence were read, including scanned pages.
- Keep a record of the checks, so they can be shown if asked.
How LIA is built around this
LIA keeps evidence, inference and gap apart, so you can see which parts of an answer rest on the file and which do not. Show working sets out the reconstruction, the counter-reading and what the conclusion depends on. On a Matter with three or more documents, Split a large search searches the files one at a time and lists each as found or not found with a short quote, so the record shows what was read. Deep Review runs two workings and sets out what they agree on, contest and still leave open. LIA is not a law firm, and it does not replace opening the authority yourself. Try it on your own file: 150 free credits, no card.
FAQ
How many AI hallucination court cases are there? As of 19 October 2026, the AI Hallucination Cases database listed 2,202 decisions worldwide. It counts only decisions where a court found or implied reliance on hallucinated material.
Have Australian lawyers been referred to regulators for AI fake citations? Yes. Australian courts have referred practitioners to regulators in Dayal, Valu (No 2), JNE24 and Pasuengos (No 2), issued a public reprimand in Re Walker, and in Dey ordered a solicitor to pay costs personally.
What penalties do lawyers face for citing fake AI cases? Recorded outcomes include fines, fee and costs orders, struck briefs, dismissal of claims, revocation of pro hac vice admission, bars from appearing in a court, disqualification from the case, referral to regulators and, in the UK, the possibility of contempt.
Is using AI for legal research allowed? Courts have said there is nothing inherently impermissible about it. The duty is to verify what is filed. The Federal Court's GPN-AI (April 2026) sets out its expectations.