A demonstrator wearing a mask depicting Brazil's former President Luiz Inacio Lula da Silva takes part in a protest against Brazil's President Dilma Rousseff's appointment of Lula as her chief of staff, at Paulista avenue in Sao Paulo, Brazil, March 17, 2016. [Photo/Agencies]

The real's 10 percent gain so far this month led the central bank to scale back its currency intervention.

Rousseff appointed her mentor, who remains one of Brazil's most influential politicians six years after leaving office, in an effort to fight impeachment and win back working-class supporters amid the worst economic recession in decades.

The corruption probe, however, has weakened Lula's sway in Congress and there are growing signs that Rousseff's main coalition partner is ready to abandon the unpopular government.

Brazil's powerful industry lobby, the CNI, said the political crisis was having "catastrophic" consequences for businesses and called on the country's politicians to overcome their differences to restore confidence.