Brazil's far-right President-elect Jair Bolsonaro has convinced prominent anti-corruption judge Sergio Moro to lead the country's justice ministry.
Mr Moro said it was an "honour" to be asked to be the minister overseeing justice and public security.
But his appointment is likely to fuel allegations that his high-profile anti-fraud probe was politically motivated.
Operation Car Wash, as his inquiry was known, was accused of unfairly targeting left-wing politicians.
Its biggest scalp was leftist ex-President Luiz Inácio Lula da Silva, who was a frontrunner in the election before his 12-year jail sentence last April for corruption.
Mr Bolsonaro won a sweeping election victory earlier this week.
He is a polarising figure, whose praise of Brazil's former dictatorship and comments on race, women and homosexuality have raised concerns.
Mr Bolsonaro made it known earlier this week that he wanted Mr Moro to be justice minister, saying he was a person "of extreme importance in a government like ours".
The two men met in Rio de Janeiro on Thursday.
"Federal Judge Sergio Moro has accepted our invitation to be minister of justice and public security. His anti-corruption, anti-organised crime agenda and his respect for the constitution and the law will be our guiding principle!" Mr Bolsonaro tweeted.
Mr Moro later confirmed in a statement that he had "accepted the invitation as an honour".
The federal judge was in charge of Operation Car Wash, a major investigation into claims that executives at the state oil company Petrobras accepted bribes in return for awarding contracts to construction firms.
He uncovered a huge web of corruption involving top-level politicians from a broad spectrum of parties.
His crusade against corruption has made him a hero to many, but others accuse him of disproportionately targeting left-wing politicians, especially those in the former ruling Workers' Party.
Former President Lula has repeatedly said he is a victim of a political witch-hunt.