Police raid French Federation headquarters
The search at the federation's headquarters in Marcoussis, a southern suburb of Paris, was ordered by the public prosecutor in charge of financial cases.
Laporte, whose lawyer said the Federation President's home was also searched on Tuesday, is suspected of pressuring the FFR's appeals committee to reduce a sanction against Montpellier, owned by businessman Mohed Altrad, who owns the Altrad Group.
He was accused of favouritism after it emerged that a company he owns had signed an image rights contract with the Altrad Group in early 2017.
He eventually pulled out of the 150 000-euro (184 000 dollars) deal but the case was investigated by the French Sports Ministry before being passed to the public prosecutor.
This month the federation signed a major shirt sponsorship deal worth "at least 35 million euros" with the Altrad Group, an industrial equipment and services company.
Despite the continuing inquiry, Laporte that the FFR's ethics and deontology committee had determined the new deal with Altrad would not create a "conflict of interests".
"Today, I take responsibility for putting a flagship of French industry on the shirt to develop our sport," Laporte said when the deal was announced.
Laporte, a former France and Toulon coach, was French Secretary of State for Sports from 2007-09 and was elected to the top FFR post in 2016.
He has announced he will stand for re-election in 2020, which would make him the boss of French rugby when the country hosts the World Cup in 2023.