The referee who booked Mario Balotelli while the Nice striker was complaining of racist abuse has said he "didnt hear insults or shouts from the stand" during Saturdays match at Dijon.
"If I had heard 'monkey chants' as indicated in the query by Nice, I would at no point have given Mario Balotelli a yellow card," Nicolas Rainville said in a statement from French referees' union SAFE on Wednesday.
"I can understand such a reaction from a player affected by these kinds of insults," he added.
French football authorities said the league's disciplinary commission will look into the case on Thursday.
An appeal was launched by two French anti-discrimination organisations on Monday for witnesses in the ground to come forward and help identify the culprits.
It is not the first time Balotelli, whose biological parents are from Ghana, has been the victim of racist abuse.
Last season Bastia were hit with a suspended one-point deduction and three-game partial stand closure by the French League over the behaviour of some of their fans.