An important minister in Brazil's interim government has stepped aside over a leaked recording in which he appears to discuss using Dilma Rousseff's impeachment to derail a corruption investigation.

Romero Juca, planning minister, said on Monday he would step aside from the next day. Although he did not resign, he was not expected to return, the Globo news site reported quoting sources close to Michel Temer, the acting president.

The scandal threatens Temer only 11 days after taking power from Rousseff, whom the Senate suspended as president on May 12 at the start of an impeachment trial on charges of breaking government accounting rules.

Juca, who is Temer's right-hand man, had been due to help lead the team asking Congress to approve urgent measures aimed at pulling Brazil out of recession.

He said that he would return to his seat in the Senate instead.

The Folha newspaper released what it said were recordings of conversations in March between Juca and Sergio Machado, a former oil executive.

'National pact'

The recordings were allegedly made secretly by Machado who, like Juca, is the target of an investigation into massive embezzlement centred on state oil company Petrobras.

In the conversations, Juca is heard calling for a "national pact" that he appears to suggest would stop the investigation, known as Operation Car Wash, in which dozens of top-ranking politicians from a variety of parties, as well as business executives, have been charged or already convicted for involvement in the Petrobras scheme.

In comments immediately taken up by Rousseff and her supporters as evidence for her claim that the impeachment process is a coup in disguise, Juca said: "We need to change the government to stop this bleeding.

"I am talking to the generals, the military commanders. They are fine with this, they said they will guarantee it."

He also said that he has been clearing his plans with justices on the Supreme Court, which oversees impeachment proceedings.

WATCH: Was President Dilma Rousseff's impeachment a coup?

Although Temer came under pressure from opponents and the Brazilian media to dismiss Juca, he made no comment after brief discussions on the matter with allies at the Senate building.

Temer took over from Rousseff automatically on May 12 because he was vice president, but he is hamstrung by abysmal approval ratings and faces major challenges to his authority and legitimacy as leader of his centre-right government.

Hecklers greeted Temer at the Senate by repeatedly shouting "Putschist!" Protesters were also out in the Argentine capital Buenos Aires, where Jose Serra, the new Brazilian foreign minister, was visiting.

"Out with Temer, out with Serra," they chanted.

Rousseff party's reaction

The senior member of Rousseff's Workers' Party in the lower house of Congress, Afonso Florence, said the scandal could "lead to the cancellation" of the impeachment process.

Juca did not deny the authenticity of the secret recording, but said that his comments had been in reference to stopping the "bleeding" of Brazil's economy, not the Car Wash probe.

The Petrobras probe has seen prosecutors go after many of Brazil's most powerful figures. Rousseff herself is suspected of obstruction of justice, although she has not been accused of corruption for personal gain.

Temer has promised a fresh start for Brazil after growing economic and political paralysis under Rousseff.

Despite the disarray caused by Juca, the new government may hope to portray his departure as proof that corruption will not be tolerated.

However, news that Juca's replacement in the planning ministry, Dyogo Henrique Oliveira, has been the target of a separate corruption inquiry is likely to cause fresh embarrassment.