Brazil President Jair Bolsonaro was embroiled in a government crisis on Thursday after a key ally accused him of washing his hands of a campaign finance scandal and sending his son to manage it.

Bolsonaro, who is six weeks into his presidency, is under pressure over reports that one of his ministers -- a former leader of his party -- may have misused campaign funds in last year's election.

Rodrigo Maia, the president of the Chamber of Deputies, accused the president of using Carlos Bolsonaro to "ask a minister to resign" rather than finding a solution himself.

"It's a huge risk for a government that needs to show leadership and unity because there are some important challenges," said Maia, who is from a party allied to Bolsonaro's PSL.

Gustavo Bebianno, Secretary General of the presidency and former head of the PSL, is suspected of involvement in a scam in which fake PSL candidates were registered during last year's election campaign in order to obtain funds.

Bebianno, who was one of Bolsonaro's main campaign organizers, tried to play down the crisis and claimed to have spoken several times with the president at a time when the far right leader was recovering from surgery in hospital.

But Carlos, one of the president's four sons, caused a storm on Thursday with a tweet denying that those meetings ever took place.

Bolsonaro, who left hospital on Wednesday after a 17-day stay, then accused Bebianno of "lying" and said he'd asked police to open an investigation into his minister's connection to the illicit campaign financing.

"The government is escalating a problem," Maia told GloboNews channel. "It gives the impression that the president is using his son to ask Bebianno to resign."

Bebianno vowed Thursday to hang on.

"If there's a problem, he (Bolsonaro) must find a solution, he cannot... get his family to intervene as that creates insecurity," said Maia.

Carlos, a councilor for Rio de Janeiro, is not the only Bolsonaro son involved in a scandal.

His eldest, Flavio, a senator, is suspected of involvement in illegal financial transactions.