French police are searching the headquarters of the organisers of the Paris 2024 Olympic Games.
Officials say the raids are part of two preliminary corruption investigations.
The BBC understands the probes are in connection with the attribution of contracts for building projects linked to the summer games.
A spokesperson for the Paris 2024 organising committee told the BBC the body is "co-operating fully with the investigators".
On Tuesday, anti-corruption investigators arrived unannounced at the headquarters of the Olympics organising committee in Saint-Denis, a Paris suburb, as well as at the offices of Solideo, the public body in charge of building projects for the games, the BBC's Hugh Schofield in Paris reports.
The French judicial organisation responsible for tracking down financial crime, the PNF, later confirmed to the BBC that their searches were being carried out across several locations involving the two organisations.
The 2024 Olympics take place from 26 July to 11 August, with the Paralympics running in September.
Tuesday's police raids are the latest episode affecting France's Olympic movement and sports in general in recent months.
In May, France's National Olympic Committee President Brigitte Henriques resigned in a move that surprised many sports experts.
No reason was given for Ms Henriques' decision, but it came amid reports of intense infighting in the organisation.
Earlier in the year, the bosses of France's football and rugby federations stood down amid high-profile scandals.