Brazil's top prosecutor has reportedly requested permission to detain several officials with the ruling Brazilian Democratic Movement Party (PMDB) for allegedly seeking to block a corruption investigation.
Top Brazilian newspapers reported on Tuesday that Prosecutor General Rodrigo Janot had called on the Supreme Court to authorize the arrest of Senate President Renan Calheiros, ex-Brazilian President Jose Sarney, Senator Romero Juca and lawmaker Eduardo Cunha.
The four are accused of trying to obstruct a probe known as "Operation Car Wash," which is focused on graft involving engineering firms and the state-controlled oil company, Petrobras, between 2003 and 2014.
The individuals, however, have denied any attempt to halt the inquiry.
The alleged evidence against the PMDB figures came from secret recordings of conversations made by a former oil executive, Sergio Machado, who is cooperating with prosecutors in a plea bargain.
In addition to the arrests, the Brazilian chief prosecutor has also requested Calheiros be removed from the Senate presidency.
The possible detentions could weaken the new administration of interim President Michel Temer as all the men are from his governing party.
Temer took the reins after the suspension of President Dilma Rousseff last month for her impeachment trial.
The impeachment bid was launched over allegations that Rousseff fiddled with government accounts in 2014 so she could increase public spending as a means of wooing voters for re-election.
Rousseff herself has condemned the impeachment drive as a coup, pledging to fight on during her trial.
Brazil has been the scene of a major political turmoil over the past few months with its economy dealing with severe recession.