The French League have opened an investigation into alleged racist remarks made by an assistant referee to AJ Auxerre midfielder Kamel Chafni at Stade Brest on Saturday.
"(LFP president) Frederic Thiriez has ordered an investigation so that the matter can be clarified as soon as possible," the LFP said in a statement on Sunday.
Moroccan Chafni claimed assistant referee Johann Perruaux told him 'get lost, Arab'. Chafni reported it to referee Tony Chapron but was booked and then sent off in the 55th minute.
"This matter must be cleared up. Some Brest players heard the same thing. So I don't think it's the player's imagination," Auxerre president Gerard Bourgoin was quoted as saying by sports daily L'Equipe on Sunday.
"There is a foul that is not sanctioned, I got to the assistant referee to tell him it's not normal," Chafni told L'Equipe.
"He answers: 'get lost, Arab' (...) I go to the field referee and I tell him what happened and he gives me a yellow card. I tell him it is unacceptable and he shows me a red card."
Chapron denied his assistant had made a racial slur.
"I deny all allegations," he told reporters after the game.
"I know the man (...) and I can tell you that he would never make racist remarks."
Brest won the match 1-0.