Brazilian President Dilma Rousseff's former campaign treasurer and her chief of staff have been placed under investigation in the Petrobras mega corruption scandal, the local press is reporting.
It would be the first time top members of Rousseff's administration have been targeted directly in the widening investigation, which has already implicated her ruling Workers Party in massive graft at the state-owned oil giant.
Two leading newspapers - O Estado de Sao Paulo and O Globo - on Sunday (local time) reported that the Supreme Court has authorised investigations into Communications Minister Edinho Silva, who was the treasurer of Rousseff's 2014 re-election campaign, and Rousseff's chief of staff, Aloizio Mercadante.
The reports said the head of a construction company implicated in the Petrobras scandal, Ricardo Pessoa, told prosecutors that he made hefty campaign donations to both men to get or keep Petrobras contracts for his firm, UTC Engenharia.
The scandal involves an estimated US$2.1 billion (NZ$3.3 billion) loss from inflated Petrobras contracts that went to a network of construction companies, which allegedly used the money to pay off politicians.
Rousseff was chair of the Petrobras board during most of the 10-year period when the corruption is alleged to have occurred, but she has not been personally implicated.
But the two latest cases bring the scandal into her inner circle just days after charges were brought against the treasurer of her Workers Party and a former chief of staff of ex-president Luiz Inacio Lula da Silva, Rousseff's predecessor and political mentor.
"I support all these acts being investigated, to clear up any doubts," minister Silva said in a statement to AFP Sunday, without confirming that he was under investigation.
He said he was confident his actions as Rousseff's campaign treasurer were above board.
Rousseff, who was re-elected with 52 percent of the vote in October, has watched her popularity collapse as the scandal has unfolded against the backdrop of a worsening economic situation.