Brazilian court approves adding current, former Rio de Janeiro governors to oil graft probe

FILE - In this Feb. 12, 2015 file photo, Rio de Janeiro Governor Luiz Fernando Pezao speaks during a press conference about host cities for football matches for the 2016 Rio Olympics in Rio de Janeiro, Brazil. Brazil's top appeals court on Thursday, March 12, 2015, approved a request from federal prosecutors to open an investigation into Pezao in connection to a kickback scheme at state-run oil company Petrobras. Pezao is one of dozens of current and former officials under investigation. All officials have denied any wrongdoing. (AP Photo/Felipe Dana, File) (The Associated Press)

FILE - In this April 18, 2012 file photo, Rio de Janeiro's Governor Sergio Cabral attends the inauguration of a new Peacemaker Police Unit (UPP) in the Fazendinha slum inside the Alemao slum complex in Rio de Janeiro, Brazil. Brazil's top appeals court, on Thursday, March 12, 2015, approved a request from federal prosecutors to open an investigation into the former governor in connection to a kickback scheme at state-run oil company Petrobras. Cabral is one of dozens of current and former officials under investigation. All officials have denied any wrongdoing. (AP Photo/Victor R. Caivano, File) (The Associated Press)

Brazil's top appeals court has approved a request from prosecutors to open an investigation into the former and current governor of Rio de Janeiro state in connection to a kickback scheme at state-run oil company Petrobras.

A court statement released Thursday says it approved the investigation into Rio Gov. Luiz Pezao and former Gov. Sergio Cabral. Also to be investigated is Gov. Tiao Viana of Acre state.

Last week, prosecutors were given approval to investigate dozens of federal congressmen and some former top executive branch officials in connection to the Petrobras case.

Prosecutors say they've uncovered the biggest corruption scheme ever discovered in Brazil. The case involves at least $800 million in bribes and other funds allegedly paid by top construction and engineering firms in return for inflated Petrobras contracts.