According to the BBC, Brazilian reports allege that Nuzman acted "as an intermediary for a 'cash for votes' scheme targeting African delegates of the IOC in the run up to the 2016 allocation" for Olympic host city.
The 75-year-old Nuzman was escorted to a police station on Tuesday with his lawyer for questioning. Detention warrants have been issued for both Nuzman and his colleague, Arthur Cesar de Menezes Soares Filho. An Associated Press photographer witnessed the police removing a computer, documents, and suitcases from Nuzman's residence. All of his assets have been frozen, according to the BBC.
The headquarters of the Brazilian Olympic Committee were also searched. Brazilian police told local media that 70 police officers conducted search and seizure operations like the one on Nuzman's residence in 11 different locations in Brazil and France.
"Operation Unfair Play" is being conducted in conjunction with French and American police.
Nuzman has held his position as president of the BOC since 1995 and headed the Rio Olympic organizing committee.
The former governor of Rio, Sergio Cabral, received a 14-year jail sentence in June for corruption and money laundering in conjunction with Rio Olympic Games construction projects.
"I can confirm that [Nuzman] did not commit any irregularity," Nuzman's lawyer, Sergio Mazzillo, said to the press. "Unfortunately, this has created a media spectacle."
A similar probe is ongoing in the United States, as the BBC reported in June that the FBI and IRS are investigating the awarding of the 2021 IAAF World Championships to Eugene, Oregon. The city, home to the Historic Hayward Field at the University of Oregon, was awarded the event in 2015 without undergoing the formal bidding process with the IAAF.