"There have been 28 requests for new investigation files... which involve 54 politicians who have immunity," a spokesman for the top prosecutor told, referring to the growing scandal which has touched President Dilma Rousseff's government.
The names of those who will be placed under investigation if the court gives the go-ahead will not be revealed for the time being as the politicians have immunity - although prosecutor general Rodrigo Janot has asked for that to be lifted.
The scandal, which investigators have dubbed Operation Car Wash, concerns a huge kickbacks scandal estimated at some USD 3.8 billion at state-owned oil giant Petrobras.
Federal prosecutors indicate some two dozen companies, chiefly top construction firms, paid massively over the odds for service contracts with Petrobras with up to three per cent creamed off in corrupt payments to politicians, mainly government allies.
Brazil's public prosecution service last month urged the firms caught up in the decade-long scandal pay some USD 1.5 billion in damages as well as yet-to-be-specified fines.
Authorities are questioning a clutch of former Petrobras and construction firm executives after one former executive at the oil firm blew the whistle on the scheme a year ago, as he seeks a plea bargain with investigators.
The scandal is the largest ever to hit Brazil, according to the public prosecution service.
Some of those questioned by police as they seek to have their own potential sentences reduced say the kickbacks were paid into politicians' personal bank accounts or into party coffers.
The list of names handed over to the Supreme Court by Janot opens a new phase in the investigation given the potential ramifications for lawmakers, while Petrobras itself has seen its reputation take a dive.
Last week, Moody's rating agency downgraded the company's stock into junk territory - a fourth downgrade in as many months with Petrobras not just embroiled in the kickbacks fallout, however, having failed to release much delayed verified 2014 earning results to restore investor confidence.
Petrobras, the largest company in the world's seventh-largest economy, once was considered one of Brazil's best and most prestigious businesses.
However, Moody's on Tuesday dropped its unsecured debt rating from Baa3 to Ba2, two steps into junk territory, amid downward spiraling profits.