A Brazilian businessman said in an interview that President Michel Temer heads the country's biggest and most dangerous criminal organisation.

Temer "is the head of the criminal organisation that operates in the Chamber (of Deputies)," Brazil's lower house of Congress, Joesley Batista, one of the owners of multinational meatpacking giant JBS, said in the interview on Saturday.

Batista said a mafia of politicians continually demanded that he pay bribes and make illegal donations to election campaigns; in return, his companies received favours or were allowed to operate unhindered, reports Efe news.

He added that the group's leaders included Temer and Eduardo Cunha, a former lower-house speaker and one of the highest-profile politicians to be sentenced to prison in the sprawling Car Wash investigation into a $2 billion bribes-for-inflated contracts scheme centred on state oil company Petrobras.

"The one who's not in prison (among the group's members) is in (the presidential palace) Planalto. That group is very dangerous. You can't argue with them," Batista said in the interview.

He said Temer called him every time he needed campaign donations for his Brazilian Democratic Movement Party (PMDB) and its political allies or money for personal reasons.

"Temer is very direct in (asking for money). He's not a person who's careful with that," Batista said.

Batista said the payments were necessary because the group had control over offices that were crucial to JBS' operations, including agencies linked to the Agriculture Ministry.

The illegal funding initially was channeled through lobbyist Lucio Funaro and then subsequently through Cunha.

Batista, who has entered into a plea deal with prosecutors, returned to Brazil last week after having been authorised to leave the country due to alleged threats against his family.

Last month, Brazil's Supreme Court launched a probe into the President based on allegations from Batista and his brother, Wesley Batista, that Temer encouraged the payment of secret money to Cunha.

Temer, who served as ousted President Dilma Rousseff's Vice President from 2011 to 2016, turned against his predecessor, supported the impeachment process and eventually succeeded her in office.

Earlier this month, Temer and Rousseff were acquitted in a case pertaining to the financing of their successful 2014 election campaign.