Brazil's presidential chief of staff resigned amid a scandal over reports that his wealth increased twentyfold in the past four years, officials said.

Antonio Palocci submitted his resignation on Tuesday to President Dilma Rousseff, who accepted it and named Workers Party, or PT, Sen. Gleisi Hoffman to replace him.

Palocci, considered the top aide to Rousseff, defended the legality of his actions in a statement released by the government and said he decided to resign from the Cabinet to avoid harming the administration.

His resignation came a day after Attorney General Roberto Gurgel rejected a request from the opposition to investigate the source of Palocci's sudden wealth, arguing that there were no indications of criminal behavior.

Palocci's wealth soared during the past four years, when he served in Congress and ran a consulting firm, the Folha de São Paulo newspaper reported.

Last year, when Palocci served in Congress and ran Rousseff's successful election campaign, his consulting firm took in about 20 million reais ($12.5 million), Folha de Sao Paulo said.

Palocci said in an interview with Globo television that he was not involved in influence peddling and his consulting work did not pose a conflict of interests.

He confirmed the income figures cited by the press but refused to identify his clients.

Palocci served as finance minister from 2003 to 2006 under former President Luiz Inacio Lula da Silva.

He was forced to resign amid a corruption scandal that included allegations of sexual misconduct.

Palocci was tried and acquitted of the charges.