Rio de Janeiro police launched raids on Tuesday against "an international corruption scheme" accused of bribing the IOC to vote for the city's bid to host last year's Olympic Games.
Brazilian law enforcement officials were conducting searches to probe "the buying of votes for the election [of Rio] by the International Olympic Committee as the venue for the 2016 Olympics," police said in a statement.
Seventy police officers, joined by French officials, fanned out across Rio to search 11 sites and serve two arrest warrants, the statement said.
Globo television reported that police were searching the house of Brazil's Olympic Committee chief, Carlos Nuzman, in Rio's posh Leblon neighborhood.
According to the report from Brazil's biggest news organization, Nuzman is suspected of taking direct part in bribery of the IOC and of acting as an intermediary between bribe givers and takers.
The Rio Games were generally credited with being a sporting and organizational success, but revelations of massive corruption during the preparations have tarnished the legacy.
In June, former Rio governor Sergio Cabral was sentenced to 14 years in prison. He was convicted of bribery and money-laundering, including participation in the embezzlement of 220 million reais ($64 million) from public works projects such as Rio's iconic Maracana soccer stadium.
The probe into the alleged vote buying, dubbed "Unfair Play," started nine months ago, police said. Brazil had asked France and the US for help.
Globo reported that the two people wanted for arrest included businessman Arthur Soares, who won lucrative contracts from Rio's government in the spending spree ahead of the Games. He was reported to be living in Miami.
French authorities have been conducting their own probe into the awarding of the 2016 Games. Rio won hosting rights in a 2009 vote of IOC members in Copenhagen, beating Chicago, Madrid and Tokyo.
French newspaper Le Monde reported that Soares, known in Brazil as "King Arthur," had paid $1.5 million to the son of one IOC member before the vote.