RIO DE JANEIRO, Sept. 5 (Xinhua) -- Brazilian federal prosecutors on Tuesday launched an investigation into a suspected bribery scheme by Rio de Janeiro state officials to secure the rights to host the 2016 Olympic Games.

The investigation, dubbed Operation Unfair Play, targets Rio's former governor, Sergio Cabral, who is under arrest for other crimes, as well as his associate, Arthur Soares, who lives in the U.S., and his partner, Eliane Pereira, who was arrested early in the day in the capital Rio, according to the Agencia Brasil (EBC) news agency.

The probe is to collect testimonies and evidence that the suspects paid the then president of the International Association of Athletics Federations (IAAF), Lamine Diack, 2 million US dollars to elect Rio as host city of the summer games.

The head of the Brazilian Olympic Committee, Carlos Arthur Nuzman, was also taken in for questioning.

Seven cities bid for the rights to hold the games, and in the final round, Rio defeated three others that were shortlisted, including Chicago, Tokyo and Madrid.