French Rugby Federation (FFR) president Bernard Laporte's alleged conflict of interest case has been sent to the public prosecutor by sports minister Laura Flessel.
Laporte is accused of influencing a federation committee to reduce penalties imposed on Montpellier owner Mohed Altrad.
It came after Altrad's eponymous business signed an image deal with Laporte's BL Communication.
Consequently, French sports minister Flessel has given justice officials the conclusions of an investigation into an alleged conflict of interest involving Laporte.
Former France coach, and later Secretary of State for Sports, Laporte eventually pulled out of the deal worth €150,000 ($178,000).
But the report found that an FFR appeals committee had reduced a sanction against Altrad, whose company sponsors the French national team, following a phone call from Laporte to the committee's chairman.
Montpellier's €70,000 fine was reduced to €20,000 and a one-game stadium ban cancelled after Laporte's intercession.
Altrad had also donated large sums of money to France's successful bid to host the 2023 World Cup.
Although Laporte was not the bid committee's head, he was a major driving force behind the country's success.
Laporte has denied accusations he pressured the French Federation's appeals board to reduce sanctions against the Top 14 club.
In a statement late on Monday, the French sports ministry said Laporte contacted the appeal commission's president on June 30 and stressed that the phone call resulted in "a change of decision from commission members. Evidence is lacking so far to know the exact content of the phone call."