Paris Saint-Germain president Nasser Al-Khelaifi has called on Bastia player Brandao to be given a heavy punishment after he allegedly headbutted Thiago Motta after Saturday's game.
Video footage emerged after the PSG's 2-0 win over Bastia which appeared to show Brandao walking over to Motta in the tunnel and thrusting his head towards his.
And Al-Khelaifi has come out in criticism of Brandao, insisting the authorities have to punish him severely.
"This is very serious," the president told reporters. "We cannot let this go. It gives a very bad image of football.
"I hope the Bastia player who did it will be severely punished. A landmark decision needs to be made and a heavy penalty handed out.
"Our role is to protect the players, and when Thiago Motta is attacked like this, we must act to counter that.
"Thiago has a broken nose and will miss four games. Everyone saw what happened. The images confirm this and there will inevitably be sanctions. We hope so. It spoils the game."