In Brazil, attorney-client privilege encompasses any activity related to the practice of law in general, and it is a principle rooted in the duty of confidentiality imposed on lawyers (Federal Law 8.906/94).
However, the Provision No. 188/2018 from the Brazilian Bar Association provides additional protection to internal investigations conducted by lawyers with the purpose of supporting their client's defense in the context of criminal proceedings, whether administrative (criminal investigations/inquiries/precautionary measures) or judicial (criminal lawsuits). The Provision states that lawyers may directly take the investigative measures that are necessary to clarify the facts, such as conducting interviews, data collection and research, and obtaining information available from public or private agencies, among other things. During the investigation, the lawyer must preserve the confidentiality of the information collected and will not have a duty to inform the authority about the results of the investigation.
From a civil procedure perspective, the Brazilian Civil Procedure Code determines that parties are not required to testify about facts that are protected by professional confidentiality (article 388). From a criminal procedure perspective, the Brazilian Criminal Code determines that the breach of a professional secrecy without good cause is considered a crime (article 154). Thus, besides the attorney-client privilege's rules, the Brazilian legal system also protects professional secrecy in general.
The issue of privilege in interviews with employees during internal investigations is not specifically regulated under Brazilian Law. On one hand, it is likely that the interview of an employee during internal investigations will be deemed to be subject to legal privilege, if the interviewers are all lawyers licensed to practice in Brazil. On the other hand, if there is someone interviewing the employee who is not a lawyer licensed to practice in Brazil, it is possible that the notes and recollections of such individual will not be subject to privilege under Brazilian Law.