Marseille defender Taye Taiwo is facing a ban from the French FA after he joined fans in an expletive-laden chant aimed at the club's rivals PSG.
Taiwo, who is set to leave the club on a free in the summer, had scored the winner for OM in Saturday's League Cup final against Montpellier and, after the game, grabbed a microphone to make his feelings known.
However, the Nigerian is set for a spell on the sidelines after the French Professional League (LFP) said it would submit his case to the federation's National Ethics Council.
"The LFP has decided to open an investigation following Taye Taiwo's behaviour after the League Cup final between Olympique Marseille and Montpellier. The League will hand the file to the Ethics Committee," read a statement.
Taiwo apologised for his actions, telling OMTV: ''I want to apologise for what I sang into the microphone at the Stade de France on Saturday night.
''Everyone has told me that it was wrong to have done that and it made them feel sick in the heart. Me too. Now I feel bad for having done that. I was euphoric. We had to win and we sang. I apologise again.''
He also extended the apology to anyone who was offended by his language.
''I apologise to all Parisians and all that found my words shocking,'' he added. ''I have great respect for the Parisians. I was happy because we had just won the cup, the fans were singing and I started to sing along. The mood after the victory, it was like at the Stade Velodrome... the fans were very happy and I sang with them.''
Marseille and PSG have had to play their games against each other behind closed doors this season because of their supporters' behaviour.
Asked what he thought of the incident on Saturday, Marseille boss Didier Deschamps replied: "I did not hear it. It will give you something to write about. The less you write about it, the better it is."
Meanwhile, Marseille defender Stephane Mbia has been ruled out until mid-May with an adductor muscle injury, the club have announced.
The Cameroon international went off in the early stages of Marseille's 1-0 win against Montpellier in the Coupe de le Ligue final on Saturday.
Manager Deschamps said: "The news is not good. He has a problem with the adductor muscle. I do not think he will return before mid-May.''
It means OM will be without Mbia for the crucial run-in, with the team currently two points behind leaders Lille at the top of Ligue 1, albeit with a game in hand.