Brazil's top prosecutor brought new charges against Senate President Renan Calheiros on Monday, accusing him of taking part in corruption at state oil company Petrobras and asking the Supreme Court to remove him from office.
Prosecutor General Rodrigo Janot's request comes just a week after Calheiros was nearly removed in a separate embezzlement case.
Janot alleges that Calheiros received part of a donation of 800,000 reais ($240,000) in 2010 from an oil and gas contractor in return for keeping a senior Petrobras executive in the post, where he was later convicted of currying favors.
Calheiros rejected the allegation in an emailed statement, and said he was willing to cooperate with any investigation.
It was not clear when the Supreme Court would take any action on the charges, but the justices enter into recess after this week and do not return to work until Feb. 1.
Monday's charges were the first that specifically tied Calheiros to the massive corruption investigation centered around state-run oil company Petrobras, where a political kickback scheme played out for years.
In the embezzlement case, Calheiros was indicted on Dec. 1 by the Supreme Court over allegations of misusing public funds in a nine-year-old case involving the payment of child support for a daughter from an extramarital affair.
A Supreme Court justice ruled last week that Calheiros should be removed from his leadership role, but the full court overturned the injunction, defusing a standoff that threatened to derail the government's agenda of economic reforms.
Under Brazil's constitution, members of Congress can only be tried by the Supreme Court, which often takes years to rule on major investigations because of an extensive backlog of cases.
($1 = 3.35 reais)