A Brazilian Supreme Court justice has blocked former President Luiz Inacio Lula da Silva from accepting a Cabinet appointment that would have helped the ex-leader avoid corruption charges.
Supreme Court Justice Gilmar Mendes, who released his decision late Friday, said Lula's Cabinet post "could amount to an act of fraud against the constitution."
Cabinet ministers in Brazil have immunity from prosecution in criminal court and can only be tried before the Supreme Court.
The controversial appointment by current President Dilma Rousseff would have halted a criminal investigation of Lula in a wide-ranging probe into corruption and money laundering at the state-owned oil giant, Petrobras.
Lula, who served as Brazil's president from 2003 to 2010, had denied he was involved in any corruption.
Prosecutors said more than $2 billion was paid in bribes and other funds by the nation's biggest construction and engineering firms in exchange for inflated Petrobras contracts.
Dozens of political figures, including close allies of Rousseff and former Petrobras executives, are under investigation.