On July 14, 2025, Brazil’s Superior Court of Justice (STJ) issued a landmark ruling reaffirming attorney-client privilege — even after the termination of the professional relationship and in cases where the attorney seeks to invoke “self-defense.”[1].

The case sparked debate due to the lack of legal provisions governing cooperation agreements executed between attorneys and criminal authorities before the enactment of Law No. 14.365/22. This law amended the Statute Governing the Practice of Law in Brazil to expressly prohibit attorneys from entering into cooperation agreements providing current or former clients’ information to criminal authorities[1].

In the case reviewed by the STJ, the defendant’s former attorneys entered into a plea agreement that triggered Operation Silício[2], an investigation into alleged crimes including money laundering, tax evasion, and procurement fraud.

According to the cooperating attorneys, their client had arranged for the issuance of fraudulent invoices through the law firm to create a slush fund used to evade taxes and launder the illicit proceeds. The attorneys also alleged that part of this fund was used to pay bribes to public officials to secure a federal contract, therefore defrauding public bids.

During the investigation, authorities authorized precautionary measures including freezing of assets and search and seizure operations, which led to the obtation of emails, spreadsheets, and fictitious invoices.

The defendant — represented by new counsel — filed a habeas corpus petition before the Federal Regional Court of the 3rd Region (TRF3), arguing that the plea agreement was void and that all evidence derived from it should be excluded. The defense claimed that the agreement was based on confidential information obtained during the attorney-client relationship, protected under the Statute Governing the Practice of Law in Brazil.

The defense requested the annulment of the plea agreement and all resulting evidence, as well as the dismissal of the criminal investigation, due to a violation of attorney-client privilege.

TRF3 rejected the petition, reasoning that:

• The information provided by the cooperating attorneys was supported by evidence obtained during the search and seizure operations.
• Law No. 14,365/22, which prohibits cooperation agreements involving former clients, only applies to agreements executed after its enactment.

However, the STJ overruled this decision, ruling that the portion of the plea agreement concerning the former client — and all evidence derived from it — must be annulled and removed from the case file.

According to the presiding Justice, “…the principle that an attorney cannot incriminate their client must prevail, as allowing otherwise would undermine the right to a proper defense.” The Court emphasized that trust between attorney and client is a cornerstone of legal advocacy and criminal justice.

A critical point: in this case, the investigation was initiated based on the attorneys’ plea bargain, meaning that the evidence gathered — even indirectly — stemmed from privileged information.

The STJ’s analysis focused on the voluntary disclosure of confidential client information by attorneys. In this context, the Court reaffirmed that cooperation agreements made in violation of attorney-client privilege are inadmissible, even when invoked as a form of self-defense by the attorney.

This ruling does not imply that attorney-client privilege is absolute. The Statute Governing the Practice of Law in Brazil provides for exceptions in criminal investigations. For example, access to privileged documents and information may be permitted if there is evidence that the attorney committed a crime and the client is formally under investigation as a co-conspirator, as outlined in §7 of Article 7 of the Statute.

[1] Article 2 of Law No. 14,365 added §6-I to Article 7 of the Brazilian Bar Statute (Law No. 8,906/94).

[2] Federal Police Cracks Down on Crimes Against the National Financial System — Federal Police

[1] STJ, RHC No. 194,064/SP, Fifth Panel, Rapporteur: Justice Reynaldo Soares da Fonseca, adjudicated on July 14, 2025.