AI Regulation Tracker / Enforcement

Parana Court Fines Self-Represented Lawyer R$20 Million for Citing a Fake STJ Precedent Produced by AI

Regulatory summary: On June 30, 2026, the 9th Civil Chamber (9a Camara Civel) of the Tribunal de Justica do Estado do Parana (TJPR), in case 0025387-22.2025.8.16.0001, sanctioned lawyer Giovanni Antonio de Luca, who was representing himself, for litigancia de ma-fe (bad-faith litigation) after he cited a Superior Court of Justice precedent, AgInt.

The 9th Civil Chamber of Brazil's Tribunal de Justica do Parana found bad-faith litigation after a lawyer cited a Superior Court precedent that did not exist in the official repository, set the penalty at 2 percent of his own R$1 billion claim, and referred him to the OAB-PR for disciplinary review. The court held that using AI to draft filings does not remove the duty to verify what is cited.

Primary source

By Anthony Guerriero, Founder, The Leveraged Years · Reviewed by The Leveraged Years Editorial Desk · Published July 9, 2026 · Last updated July 9, 2026

Parana Court Fines Self-Represented Lawyer R$20 Million for Citing a Fake STJ Precedent Produced by AI regulation briefing

The Leveraged Years AI Regulation Tracker

Key takeaways

A Brazilian appellate chamber attached a concrete, high-value penalty to citing a nonexistent AI-generated precedent. De Luca had sued the delivery platforms iFood, Rappi Brasil, and Uber Brasil, alleging misleading discount advertising, and supported his position with AgInt no REsp 1.988.733/SP, attributed to Minister Moura Ribeiro of the STJ Third Panel and dated March 20, 2023. The court checked the STJ repository, found no such judgment, and treated the citation as fabricated. It then characterized the conduct as bad-faith litigation, set the fine at 2 percent of the declared R$1 billion claim, and referred the lawyer to the OAB-PR.
Lawyers and self-represented litigants filing in Brazilian courts; law firms adopting generative AI for research and drafting; compliance and risk leads at firms that bill AI-assisted work; and legal-tech vendors selling drafting tools into the Brazilian market. Foreign counsel coordinating Brazilian litigation should note the same exposure applies to local filings they help shape.
Status: Decided.
Add a citation-verification checkpoint to your filing process: for every case, statute, or precedent produced with AI assistance, record the official repository link and confirm the holding before signing, and train staff that no AI output goes into a filing unchecked.

Regulatory Briefing

Bindingness: Binding judicial decision. This is a ruling by the 9th Civil Chamber of the TJPR in a specific appeal, applying existing law on bad-faith litigation under the Brazilian Code of Civil Procedure (Codigo de Processo Civil). It binds the parties to that case and stands as persuasive precedent and a clear signal of how Parana courts will treat AI-fabricated citations. It is not a statute or a new regulation, so it does not create a fresh rule, but it applies established duties to a new fact pattern.
Scope: Litigation before Brazilian courts, with direct effect in Parana. It reaches any party or lawyer who submits filings containing legal authority, whether or not AI was used, because the operative duty is to verify cited precedent. Self-represented lawyers face the same duty as counsel for others; here the sanctioned party was both the plaintiff and his own advocate.
What Changed: A Brazilian appellate chamber attached a concrete, high-value penalty to citing a nonexistent AI-generated precedent. De Luca had sued the delivery platforms iFood, Rappi Brasil, and Uber Brasil, alleging misleading discount advertising, and supported his position with AgInt no REsp 1.988.733/SP, attributed to Minister Moura Ribeiro of the STJ Third Panel and dated March 20, 2023. The court checked the STJ repository, found no such judgment, and treated the citation as fabricated. It then characterized the conduct as bad-faith litigation, set the fine at 2 percent of the declared R$1 billion claim, and referred the lawyer to the OAB-PR.
Who This Affects: Lawyers and self-represented litigants filing in Brazilian courts; law firms adopting generative AI for research and drafting; compliance and risk leads at firms that bill AI-assisted work; and legal-tech vendors selling drafting tools into the Brazilian market. Foreign counsel coordinating Brazilian litigation should note the same exposure applies to local filings they help shape.
Current Status: Decided. Judgment entered June 30, 2026 by the 9a Camara Civel. The sanction and the OAB-PR referral are in effect as ordered in the ruling. Ordinary appellate remedies within the Brazilian system may still be available to the sanctioned party, but the decision itself is issued and on the public record.
Effective Date: June 30, 2026 (date of the decision).
Primary Source: https://www.tjpr.jus.br/noticias/-/asset_publisher/9jZB/content/tjpr-multa-advogado-por-litigancia-de-ma-fe-pelo-uso-de-ia-sem-zelo-e-cautela-/18319
Secondary Analysis: JOTA (Jun 2026), Migalhas, and Conjur reported the ruling, the 2 percent of R$1 billion fine, the fabricated STJ citation, and the OAB-PR referral.
Workflow Impact: Any AI-assisted legal research now needs a mandatory verification step in which a human opens each cited authority in the official court repository (STJ, STF, or the relevant tribunal) and confirms it exists and says what the filing claims, before the document is signed and submitted.
Operational Next Step: Add a citation-verification checkpoint to your filing process: for every case, statute, or precedent produced with AI assistance, record the official repository link and confirm the holding before signing, and train staff that no AI output goes into a filing unchecked.
Last Verified: July 10, 2026

Date	Jurisdiction	Rule	Affected professionals	Status or effective date
2026-07-09	Brazil (Parana)	A Brazilian appellate chamber attached a concrete, high-value penalty to citing a nonexistent AI-generated precedent. De Luca had sued the delivery platforms iFood, Rappi Brasil, and Uber Brasil, alleging misleading discount advertising, and supported his position with AgInt no REsp 1.988.733/SP, attributed to Minister Moura Ribeiro of the STJ Third Panel and dated March 20, 2023. The court checked the STJ repository, found no such judgment, and treated the citation as fabricated. It then characterized the conduct as bad-faith litigation, set the fine at 2 percent of the declared R$1 billion claim, and referred the lawyer to the OAB-PR.	Lawyers and self-represented litigants filing in Brazilian courts; law firms adopting generative AI for research and drafting; compliance and risk leads at firms that bill AI-assisted work; and legal-tech vendors selling drafting tools into the Brazilian market. Foreign counsel coordinating Brazilian litigation should note the same exposure applies to local filings they help shape.	Decided. Judgment entered June 30, 2026 by the 9a Camara Civel. The sanction and the OAB-PR referral are in effect as ordered in the ruling. Ordinary appellate remedies within the Brazilian system may still be available to the sanctioned party, but the decision itself is issued and on the public record.

Frequently Asked Questions

Is this a new AI law in Brazil?

No. It is a judicial decision by the 9th Civil Chamber of the TJPR applying existing bad-faith litigation rules in the Code of Civil Procedure to a fabricated, apparently AI-generated citation. It is binding on the parties and persuasive as precedent, but it is not a statute or regulation.

How was the R$20 million figure calculated?

The court set the bad-faith penalty at 2 percent of the value of the claim. The plaintiff had valued his own case at R$1 billion, so 2 percent of that amount is R$20 million.

What was wrong with the citation?

The lawyer cited AgInt no REsp 1.988.733/SP, attributed to Minister Moura Ribeiro of the STJ Third Panel and dated March 20, 2023. That judgment was not found in the STJ official repository, and the court treated it as fabricated.

Does the ruling say lawyers cannot use AI?

No. It says that using AI to help prepare legal documents does not remove the user's duty to rigorously verify the information cited. The sanction was for submitting a false authority, not for using software.

What happens with the OAB-PR referral?

The court sent an official communication to the Parana bar flagging a possible disciplinary breach under Article 34, XIV of the Advocacy Statute. The bar handles any disciplinary process separately from the civil case.