Police have searched the headquarters of Olympique Marseille and seized documents relating to Franck Ribery's transfer from Galatasaray to OM in 2005.
Marseille prosecutors launched an investigation last year after Ribery's former agent, Bruno Heiderscheid, filed a complaint against the player and Marseille for alleged irregularities related to Ribery's transfer from the Turkish side.
According to L'Equipe, police seized various accounting documents and files in order to check if fund transfers had been made between OM and Galatasaray and also between OM and Heiderscheid.
Ribery joined Marseille, having opted out of his deal with Galatasaray in May 2005, in order to return to France after having gone over four months without wages. He also fired Heiderscheid a few weeks before signing for Marseille, before joining agents Alain Migliaccio and Jean-Pierre Bernès.
Galatasaray appealed against the move, claiming €10 million in compensation, but the Court of Arbitration of Sport (CAS), ruled that Ribery had terminated his contract with the Turkish club at the end of the 2004-05 season on just grounds,
The French forward then left OM for Bayern Munich in 2007, on a four-year deal for a then club-record €25 million. He has since become one of the most sought-after players in the world, with Real Madrid reported to have offered around €60 million for his services this summer.