The French Tennis Federation (FFT) headquarters in Paris has been searched by police investigating Roland Garros ticket sales and modifications to the site that stages the French Open.
A lawyer for FFT president Jean Gachassin, a former France rugby international, has denied allegations the 74-year-old may have acted inappropriately in reselling tickets for the grand slam tournament to a travel agent.
French sports daily L'Equipe reported on its website that Gachassin's office had been targeted after a preliminary investigation.
Lawyer Xavier Autain told France Info: "We have to stop this fantasy. Jean Gachassin, like every leader of the federation, has the right to a certain number of tickets. He wasn't using them and allowed others to buy them, but to buy them directly. The money went straight to the federation."
The prosecutor of the Republic (PNF) said in a statement the investigation was focused "in particular on the existence of an illicit system of tickets being resold at the International tournament of France (French Open) and the manner of the award of the contract for the the renovation and expansion of the Roland Garros stadium".
The FFT said in a statement: "Investigators from the judicial police raided the premises of the French Federation Tennis, this Tuesday, May 3, 2016.
"The teams of the federation, elected officials and employees, are collaborating fully with investigators. The French Tennis Federation has no comment to make at this stage of the proceedings."