France's financial prosecutor on Tuesday said investigations had revealed that the son of the president of the International Association of Athletics Federations (IAAF) was at the center of a large corruption racket.
"The investigations revealed a large-scale system of corruption around Papa Massata Diack, son of Lamine Diack, IAAF president and influential members of the International Olympic Committee (IOC)," the financial prosecutor's office said in a statement.
"There are several consistent indications that payments have been made in return for the votes of IAAF and International Olympic Committee members over the designation of host cities for the biggest global sporting events," it added.
The investigations initially targeted the award of the 2020 games to Tokyo before extending to include the 2016 games in Rio de Janeiro.
France's deputy financial prosecutor is due to address a joint press conference with Brazilian counterparts at 1400 GMT.