Brazilian police say they have detained a lawyer representing a key convict in the mushrooming corruption scandal at the state-run oil giant Petrobras.

Police say Edson Ribeiro was detained Friday at Rio's international airport after getting off a flight from Miami.

The lawyer has been representing former Petrobras director-turned-finger-pointer Nestor Cervero. Investigators say Ribeiro was in the United States when an arrest warrant against him was issued this week.

Ribeiro was wanted for his alleged role in a scheme to keep Cervero from testifying against a billionaire investment banker.

The banker and the Senate leader for the governing Workers' Party were also detained Wednesday in connection with the plot.

They are said to have offered Cervero's family payouts in exchange for his silence during testimony to investigators.