A close ally of Brazil's acting President Michel Temer is stepping aside in a new political scandal.
Planning Minister Romero Juca was caught on tape allegedly conspiring to obstruct the country's biggest-ever corruption investigation.
In the tapes, leaked by a newspaper, he appears to talk of stopping the probe at oil giant Petrobras by impeaching suspended President Dilma Rousseff.
Mr Juca says his comments have been taken out of context.
Dilma Rousseff said the tapes prove that the impeachment process is a "political coup" designed to protect senior figures implicated in the Petrobras scandal.
She is accused of massaging budget figures ahead of her re-election in 2014, and is due to be tried in the senate in the coming months.
In the audio transcript, leaked by the Folha de Sao Paulo newspaper on Monday, Mr Juca appears to be saying the impeachment was necessary to "staunch the bleeding" and create a "political pact" needed to "stop everything and limit things."
Folha says the recording was made by the man Mr Juca was talking to, Sergio Machado.
Mr Machado is a former senator who until recently headed Transpetro, Brazil's largest oil and gas transport company.
He is under investigation over his alleged involvement in the Petrobras scandal.
The newspaper alleges he recorded the conversations with a view to negotiating a plea bargain, wanting to exchange information implicating other suspects for a lower sentence.
Mr Machado himself has not commented.
For many analysts, the context of the conversation appears to be Brazil's political crisis, and he seems to be talking about preventing further investigations into Petrobras.
In comments immediately taken up by Ms Rousseff's supporters as evidence for her claim of a coup, Mr Juca also said:"I am talking to the generals, the military commanders. They are fine with this, they say they will guarantee it."