A standoff between two justices of Brazil's Supreme Federal Tribunal (STF) has opened debate over whether the Master case, the investigation into billion-real fraud at Banco Master, could be voided. An analysis by BBC News Brasil published on Tuesday (8) examines whether the conflict between Justices André Mendonça and Alexandre de Moraes could contaminate Operation Compliance Zero and nullify acts of the case.
According to the BBC, Moraes says, based on a report he commissioned from the Federal Police within the so-called Fake News inquiry, that Mendonça may have committed, "in theory", administrative improbity, crimes of responsibility and abuse of authority, with a breach of "judicial impartiality" and "favoring certain political groups" while overseeing Operation Compliance Zero (Banco Master) and Operation Sem Desconto (INSS, the federal pension system). The document is apocryphal, unsigned by its authors, and the police itself classified it as having "no probative value".
The allegations respond to another Federal Police report, commissioned by Mendonça, on messages exchanged between Moraes and banker Daniel Vorcaro, arrested in November 2025. The conversations include a supposed request by the banker for Moraes to intervene in his favor with the Prosecutor General's office (PGR) and the Federal Police. According to G1, Mendonça unsealed those messages on September 1. Moraes replied on September 3, unsealing Federal Police intelligence reports and asking STF President Edson Fachin to investigate his colleague. On Tuesday, Mendonça preventively removed Federal Police director-general Andrei Rodrigues and intelligence chief Leandro Almada.
The Lava Jato precedent
The comparison lawyers keep returning to is Lava Jato, the corruption task force that collapsed in 2019. Leaked messages from the phone of Deltan Dallagnol, then the task force chief, showed suspicious interactions with judge Sergio Moro. The STF later found that Moro had not acted impartially and voided a series of criminal cases, including the convictions of President Luiz Inácio Lula da Silva, the BBC reports.
For criminal lawyer Marina Coelho, a professor at Insper and vice-president of the São Paulo Lawyers Institute, Moraes's counterattack aims at the broad nullification of the Master case.
"He chose attack as his defense. And that attack cannot target only Mendonça, it has to target Mendonça and the operation as a whole. In the end, the defense he can mount is a defense of nullity, because on the merits, from what we can see, it is harder", she told the BBC.
Coelho said she has no elements to state that Mendonça committed any illegality, because the case is under seal. In her assessment, what has been presented so far does not support an investigation of the justice. "A report has to have a beginning, a middle and an end. It has to state its objective, it has to be signed. Otherwise, it has no value whatsoever", she said.
What the plenary decides
Prosecutor General Paulo Gonet asked the court to void the report on Vorcaro's messages to Moraes. In the PGR's view, Mendonça should have taken the question to the full bench before ordering the initial probe. The final call belongs to the plenary. Coelho describes the document as a case of "fortuitous discovery of evidence", when an investigation finds evidence against someone who was not its original target, and says no investigation of Moraes was opened, only an analysis of the seized messages.
According to UOL, a faction that backs Moraes believes it has a majority to declare the nullity of Mendonça's acts in the Master case, though the plenary tally is seen as uncertain. Meanwhile, the crisis stays on the court's docket. In Tuesday's Second Chamber session, which was judging Andrei Rodrigues's removal, Justice Gilmar Mendes asked for more time to review the case and suspended the vote; Justice Dias Toffoli had not yet voted.