AI Hallucination Cases

This database tracks legal decisions1 I.e., all documents where the use of AI, whether established or merely alleged, is addressed in more than a passing reference by the court or tribunal.

Notably, this does not cover mere allegations of hallucinations, but only cases where the court or tribunal has explicitly found (or implied) that a party relied on hallucinated content or material.

As an exception, the database also covers some judicial decisions where AI use was alleged but not confirmed. This is a judgment call on my part.
in cases where generative AI produced hallucinated content – typically fake citations, but also other types of AI-generated arguments. It does not track the (necessarily wider) universe of all fake citations or use of AI in court filings.

While seeking to be exhaustive (558 cases identified so far), it is a work in progress and will expand as new examples emerge. This database has been featured in news media, and indeed in several decisions dealing with hallucinated material.2 Examples of media coverage include:
- M. Hiltzik, AI 'hallucinations' are a growing problem for the legal profession (LA Times, 22 May 2025)
- E. Volokh, "AI Hallucination Cases," from Courts All Over the World (Volokh Conspiracy, 18 May 2025)
- J-.M. Manach, "Il génère des plaidoiries par IA, et en recense 160 ayant « halluciné » depuis 2023" (Next, 1 July 2025) - J. Koebler & J. Roscoe, "18 Lawyers Caught Using AI Explain Why They Did It (404 Media, 30 September 2025)

If you have any questions about the database, a FAQ is available here.
And if you know of a case that should be included, feel free to contact me.3 (Readers may also be interested in this project regarding AI use in academic papers.)

Based on this database, I have developed an automated reference checker that also detects hallucinations: PelAIkan. Check the Reports Report icon in the database for examples, and reach out to me for a demo.

For weekly takes on cases like these, and what they mean for legal practice, subscribe to Artificial Authority.

Click to Download CSV
Last updated: 22 May 2026
State
Party
Nature – Category
Nature – Subcategory

Case Court / Jurisdiction Date ▼ Party Using AI AI Tool Nature of Hallucination Outcome / Sanction Monetary Penalty Details Report(s)
Collins v. Nova Association Management Partners LLC W.D. Washington (USA) 13 January 2026 Lawyer Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)
Order to Show Cause
Heiting v. I Am Beyond LLC SC California (USA) 13 January 2026 Lawyer Implied
False Quotes Case Law (2)
Warning
Wurtenberg v. The City of New York SC New York (USA) 12 January 2026 Lawyer Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)
Warning
Gharavi v. Google LLC N.D. California (USA) 12 January 2026 Lawyer Bloomberg Law
Fabricated Case Law (1)
Motion for Sanctions denied

Rodgers' declaration included a non-existent Wisconsin criminal case citation (reported by Bloomberg Law). Court found the error inadvertent, attributable to reliance on Bloomberg, and denied sanctions because conduct was neither reckless nor in bad faith.

Alami Nature Electricity Ltd. v. Nof Ganusar Agricultural Cooperative D. Nazareth (Israel) 11 January 2026 Lawyer Implied
Fabricated Case Law (1)
Legal costs denied (despite prevailing)
Garibay-Robledo v. Noem N.D. Texas (USA) 9 January 2026 Lawyer Implied
Fabricated Case Law (1)
False Quotes Case Law (1)
Warning
Esteme v. Aquitaine Co-Investment T. com. Bordeaux (France) 9 January 2026 Lawyer Implied
Fabricated Case Law (1)
⚠ Alleged AI Use
Deutsche Bank National Bank v. Jean LeTennier SC New York (USA) 8 January 2026 Lawyer Unidentified
Fabricated Case Law (2)
Misrepresented Case Law (1)
Orders affirmed; monetary sanctions imposed (counsel $5,000; defendant $2,500) and costs awarded 10000 USD
Elden v HMRC First-tier Tribunal (UK) 8 January 2026 Lawyer Unidentified
Misrepresented Case Law (4)
Order to include statements of truth about AI use
TA Orléans, Reconduite à la frontière, n° 2506907 TA Orléans (France) 7 January 2026 Lawyer Implied
Fabricated Case Law (4)
Admonishment
Sammie Dwayne McPhaul v. College Hills OPCO D. Kansas (USA) 6 January 2026 Lawyer Implied
False Quotes Case Law (5)
Misrepresented Case Law (1)
Order to Show Cause
Washburn v. Houston Arizona CA (USA) 2 January 2026 Lawyer Implied
False Quotes Case Law (1), Exhibits or Submissions (1)
Misrepresented Case Law (1)
Bar referral

Appellant Father's counsel submitted an opening brief containing misleading/inaccurate legal citations, mischaracterized case law, fabricated quotations attributed to Owen v. Blackhawk, and false quotations purportedly from the amended decree and hearing transcripts. The appellate court identified these errors, concluded they supported a potential ethics referral, and forwarded the decision to the State Bar for review.

Eric Hildebrandt v. siParadigm LLC et al. D. New Jersey (USA) 31 December 2025 Lawyer Unidentified
Fabricated Case Law (2)
False Quotes Exhibits or Submissions (1)
Misrepresented Case Law (1)
Sentencia 000126/2025 TSJ Gran Canaria (Spain) 31 December 2025 Lawyer Implied
Fabricated Case Law (1), Doctrinal Work (1)
False Quotes Case Law (2)
Misrepresented other (1)
Burnett v. The City of New York SC New York (USA) 31 December 2025 Lawyer Implied
Fabricated Case Law (1)
Order to Show Cause
Tiffany Regina Ringer v. Bank of America, N.A. N.D. Georgia (Atlanta Division) (USA) 30 December 2025 Lawyer Implied
False Quotes Case Law (1), Legal Norm (1)
Misrepresented Case Law (1)
Fine; Ordered to submit statement of training/oversight 1500 USD

Report on Recommendations can be found here.

Source: Robert Freund
M.T. Real Estate Investment Inc. v. Servis One, Inc., et al. D. Nevada (USA) 30 December 2025 Lawyer Unidentified
Fabricated Case Law (4), Doctrinal Work (1)
Briefs Struck; Adverse Costs Order; Bar Referral
Pauliah v. University of Mississippi Medical Center S.D. Mississippi (USA) 30 December 2025 Lawyer, Pro Se Litigant Unidentified
Fabricated Exhibits or Submissions (2)
False Quotes Exhibits or Submissions (1)
Monetary Sanction; CLE 5000 USD

The plaintiff's sworn declaration contained multiple fabricated quotations and manufactured deposition citations. Defendants identified the fabrications in a motion to strike; the court found the declaration filed in bad faith, struck it, and imposed sanctions under Fed. R. Civ. P. 56(h). The plaintiff admitted using generative AI to draft portions and failing to review the declaration; counsel failed to verify the citations despite attending and taking the depositions.

Mazaheri v Law Society of Ontario Ontario Law Society Tribunal (Canada) 30 December 2025 Lawyer Grok
Fabricated Case Law (1), Exhibits or Submissions (1)
Labatt USA Operating v. Friends Beverage Group SC New York (USA) 30 December 2025 Lawyer Unidentified
Fabricated Case Law (1)
Filings struck

By interim order dated March 17, 2025 the court struck defendants' opposition and cross-motion after finding the filings, drafted with AI, contained hallucinated (fabricated) case citations. The court treated the motion as unopposed thereafter.

In re S.A., D.H., and B.M., Minors CA Illinois (USA) 29 December 2025 Lawyer Implied
False Quotes Case Law (4)
Warning
N° 2506461 TA Orléans (France) 29 December 2025 Lawyer Implied
Fabricated Case Law (15)
Misrepresented Case Law (1)
Admonishment
Mag 7 Ltd. et al. v. Tederi et al. District Court, Tel Aviv-Yafo (Israel) 25 December 2025 Lawyer Implied
Fabricated Case Law (1)
Monetary Sanction; Order to amend pleading 10000 ILS
Unknown Case Number Anvers (Belgium) 25 December 2025 Lawyer Implied
Fabricated Case Law (1)
Monetary Sanction 25000 EUR

See story here.

In the matter of Bayfoyle SC New South Wales (Australia) 23 December 2025 Lawyer Implied
Fabricated Case Law (1)
Adverse Costs Order (AI misuse one of the factors); Declined to Refer to the Bar 1
Leytcorp v Mimbim Enterprises Trade Marks Office (Australia) 22 December 2025 Lawyer Implied
Fabricated Case Law (1)
Pasuengos v Minister for Immigration and Citizenship Federal Circuit and Family Court (Australia) 22 December 2025 Lawyer Unidentified
Fabricated Case Law (1)
Order to Show Cause

The court eventually granted some costs in a subsequent decision (see here).

Billups v. Louisville Municipal School District N.D. Mississippi (USA) 19 December 2025 Lawyer Grok
Fabricated Case Law (1)
Misrepresented Case Law (3)
Counsel DQ'd; monetary sanction; obligatory audit of all past filings
Report
Plaintiff's Memorandum

The court also identified five other cases in which the same firm or attorney confessed having misused AI. This despite the attorneys attending CLE training

Disability Rights Mississippi v. Palmer Home for Children N.D Mississippi (USA) 19 December 2025 Lawyer Implied
Fabricated Case Law (3)
False Quotes Case Law (5)
Monetary sanction; CLE requirement; notification to bar and other courts; attorney withdrawal. 20883 USD
Report
Plaintiff's Memorandum
Nelligan O’Brien Payne v Amy French IP Office (Canada) 19 December 2025 Lawyer Implied
Misrepresented Case Law (2), other (1)
Warning
Patrick Joseph Groulx v CSL Limited CA Michigan (USA) 19 December 2025 Lawyer Implied
Fabricated Case Law (2)
Appeal dismissed
M. [C] c/ CAF de la [Dpt CAF] TJ Périgueux (France) 18 December 2025 Lawyer Implied
Fabricated Case Law (1)
Warning
Arabyads Holding Limited v. Gulrez Alam Marghoob Alam ADGM (UAE) 18 December 2025 Lawyer Implied
Fabricated Case Law (2)
Misrepresented Case Law (4)
Mon 282508

MIO produced a prolix Defence containing multiple non-existent, miscited and misapplied authorities. The Court found AI-driven research produced hallucinatory results and that MIO failed adequately to verify authorities, amounting to reckless conduct warranting an indemnity costs order.

Wireless Investors LLC v. Semtech Incorporated, et al. D. Arizona (USA) 18 December 2025 Lawyer Implied
False Quotes Case Law (1)
Misrepresented Case Law (1)
Warning
Source: Jesse Schaefer
Russel Williams Home Services LLC v. Minleon International (USA) Limited LLC, et al. M.D. Pennsylvania (USA) 17 December 2025 Lawyer Implied
False Quotes Case Law (2)
Order to Show Cause
Burlingame v. Argo Private Client Group, Ltd. et al. S.D. New York (USA) 17 December 2025 Lawyer Implied
Fabricated Case Law (1)
False Quotes Case Law (2)
Misrepresented Case Law (1)
L.A. Housing Outreach, LLC v. Medoff CA California (USA) 17 December 2025 Lawyer Implied
Fabricated Case Law (1)
Misrepresented Case Law (1)
Reply brief struck; monetary sanction; State Bar referral 5070 USD

The court found that the majority of legal authorities in appellant counsel's reply brief were incorrect or did not support the propositions for which they were cited. The court struck the reply brief, imposed monetary sanctions of $5,070, and directed a copy of the opinion be forwarded to the State Bar.

Source: Jesse Schaefer
Angelica E. Cruz et al. v. United States of America C.D. California (USA) 16 December 2025 Lawyer Implied
Fabricated Case Law (1)
Order to Show Cause
Taylor v. Prince George’s County, Maryland D. Maryland (USA) 16 December 2025 Lawyer Implied
False Quotes Case Law (1)
Misrepresented Case Law (2)
Report
Plaintiff's Response
Dorsey v. Jones Delaware C. Ch. (USA) 16 December 2025 Lawyer Implied
Fabricated Case Law (1)
False Quotes Case Law (1)
Order to certify future filings re: AI
McMillian v. Zimmer US, Inc S.D. New York (USA) 16 December 2025 Lawyer Unidentified
Fabricated other (1)
Adverse Costs Order 9000 USD
Source: Jesse Schaefer
PRM Group, Inc. v. Paralegal Bootcamp LLC D. Maryland (USA) 16 December 2025 Lawyer Implied
Fabricated Case Law (1)
Misrepresented Case Law (1), other (1)
Show Cause Order
Liza Gardner v. Sean Combs, et al. D. New Jersey (USA) 15 December 2025 Lawyer Unidentified
Fabricated Case Law (1)
Monetary fine; Bar Referral; Order to serve order to Client 6000 USD

Counsel had already been sanctioned in different case, and professed having gone through CLE on generative AI.

Source: Robert Freund
Roll Q/25/0025 Gent (Belgium) 15 December 2025 Lawyer Implied
Fabricated Case Law (3)
Hearing on possible sanction
Advokatnævnet – Sagsnr. 2025-1655 Advokatnævnet (Denmark) 15 December 2025 Lawyer Implied
Fabricated Case Law (2)
Fine 10000
Johnson / Estate of Fisher v. City of Annapolis D. Maryland (USA) 13 December 2025 Lawyer Implied
Fabricated Case Law (1)
Misrepresented Case Law (1), Exhibits or Submissions (1)
(Attorney was dismissed by its client)
Report
City's Motion
Source: Volokh
A.M., F.A. c/ C.N.H y otros CA Río Negro (Argentina) 12 December 2025 Lawyer Implied
Fabricated Case Law (5)
Misrepresented Case Law (1)
Admonishment
Mr T De Carvalho Ferreira v Magic Life Limited & Ors Employment Tribunals (Reading) (UK) 12 December 2025 Lawyer Unidentified
Fabricated Case Law (1)
Warning
Russell v. Mells CA Florida (USA) 10 December 2025 Lawyer Unidentified
Fabricated Case Law (1)
Misrepresented Case Law (1)
Bar Referral

"Unfortunately, we're finding this problem arising more and more frequently […] When a lawyer cites imaginary legal authorities to our court as if they were law, we are compelled to refer that lawyer to the Bar because of the professional rules of conduct.

It doesn't take much moral imagination to understand why. As judges, we rely on attorneys to ethically represent their clients. We expect that representation to be zealous, honest, and competent. Indeed, lawyers owe the courts and their clients a duty to practice with competence and candor. By signing an appellate brief, a lawyer certifies that he or she has read the document and that to the best of the lawyer's knowledge, information, and belief there are "good grounds to support the document."

These ethical requirements are not excused simply because a computer program generated a faulty or misleading legal analysis. Nor is it an excuse that the attorney did not intend to mislead the court. "To state the obvious, it is a fundamental duty of attorneys to read the legal authorities they cite in appellate briefs or any other court filings to determine that the authorities stand for the propositions for which they are cited."

Obviously, that didn't happen when Ms. McLane filed this answer brief. Instead, counsel "fundamentally abdicated" her duty to the court and her client when she submitted this filing without verifying that the three cases cited in her brief said what she claimed they said. Accordingly, it is our duty to refer this matter to the Florida Bar to proceed as it deems appropriate."

Source: Volokh
South Side Area School District et. al v. Pennsylvania Human Relations Commission Pennsylvania CC (USA) 10 December 2025 Lawyer Implied
False Quotes Case Law (1)
Misrepresented Case Law (1)

See story here and here.