Reims defender Antoine Conte has been detained by French police after being accused of attacking a man with a baseball bat.
French radio station Europe 1 claim a 19-year-old man is in hospital after intervening in a heated argument between Conte and his partner.
Ligue 2 side Reims say they are awaiting the full facts before deciding on a sanction.
A statement read: "The club acknowledges with shock the deplorably violent acts attributed to Antoine Conte.
"The club's thoughts are with the player's partner and the young individual who was seriously injured. The club condemns such actions with the utmost firmness.
"The player must answer for his actions which, if proven, would bring exemplary punishment by the club."
Conte, 22, previously played for Paris Saint-Germain, making one first-team appearance, before joining Reims in 2014. He has also represented France at several youth levels including Under-21.
Club president Jean-Pierre Caillot added at a news conference: "It is a sad affair. As a man and a father I am very disturbed by the facts as they have been reported.
"This is completely against the values we embody.
"It is for the courts to decide but those familiar with Reims and people who know me know that there will be no leniency in this matter."