Marseille president Vincent Labrune has been arrested as part of an investigation into France striker Andre-Pierre Gignac's transfer to the Ligue 1 club.
Labrune, 43, was arrested by police and placed in custody on Tuesday morning in connection with a probe into commission paid as a result of Gignac's arrival at the Stade Velodrome from Toulouse in 2010 for a reported 16 million euros.
At the time, as head of the club's supervisory board, Labrune was responsible for validating all of OM's financial operations.
Labrune's predecessor as OM president and incumbent at the time of the transfer, Jean-Claude Dassier, was also arrested along with the club's current director general, Philippe Perez, a police official who spoke on condition of anonymity because the investigation is ongoing told The Associated Press..
According to RTL radio, another former Marseille president, Pape Diouf, was also arrested as part of the investigation.
The investigation was opened in 2011 while a police raid on OM's training ground offices in January 2013 saw investigators leave with a number of documents. Officials at OM, who have continually claimed their good faith in regard to the allegations, were not immediately available for comment.
Gignac, who is just one goal behind Lyon forward Alexandre Lacazette at the top of the Ligue 1 scoring charts this season, is expected to leave the club next summer on a free transfer after Labrune admitted last month that the club cannot afford to keep him.
Meanwhile, Le Point reports that French police have made numerous arrests across the country in connection with an investigation into the potential fixing of Ligue 2 games last season.
A statement on the Marseille website said: "Vincent Labrune and Philippe Perez, president and general manager of Olympique Marseille, met this morning to answer questions from investigators. The hearings today are part of an investigation which started almost two years ago, relating in particular to the conditions around former player transfers.
"Since the initiation of this investigation, the club and its leaders have continued to collaborate with justice and to contribute to the manifestation of the truth.
"The primary shareholder of the club, Margarita Louis-Dreyfus, today reiterated her determination that Olympique de Marseille will be managed in accordance with professional and ethical standards and expressed full confidence in the current management as well as the French judicial system.''
Officers swooped on addresses in Nimes, Angers, Caen and Dijon on Tuesday morning in the hope of shedding light on three of last season's second-tier matches.
All three encounters involved Nimes, who only saved themselves from relegation to French football's National divison late in the 2013-14 campaign.
The arrests were sparked after, as part of another investigation, police overheard conversations between Nimes president Jean-Marc Conrad and Serge Kasparian, the club's majority shareholder, during which the latter suggested he could arrange games to ensure the club's survival, Le Point claims.
Dijon coach Olivier Dall'Oglio, whose team beat Nimes 5-1 on April 25, and Caen president Jean-Francois Fortin, whose team drew 1-1 with the southerners on the penultimate day of the season, were among those arrested, L'Equipe reported.
Angers stated no members of their club had been among those being questioned.
Patrice Garande, the coach of now-Ligue 1 side Caen, will be questioned as a witness, L'Equipe stated.
Information from the Associated Press was used in this report.