French rugby league player knocks out referee after being yellow-carded (VIDEO)

This is the sickening moment a French rugby league player knocked out a referee after being yellow carded during a juniors French Cup match between Saint-Esteve and Toulouse.

Video footage shows referee Benjamin Casty showing a Saint-Esteve player a yellow card - which under rugby league rules suspends a player from the field of play for 10 minutes and is known colloquially as a 'sin bin.'

But instead of leaving the pitch, the player confronts the referee, before landing a huge blow to the offical's right jaw which sends him crashing to the ground unconscious.

After punching the referee, the player can also be seen brawling with opposition players - one of whom tackles him to the ground - before walking off the field.

Referee Casty, whose brother Remi plays for Super League club Catalan Dragons, was taken to hospital but avoided a broken jaw, the Independent reported.

The Saint-Esteve player, who is as yet unidentified, is now facing a possible lifetime ban from the sport.

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French Rugby League Federation president Marc Palanques promised strong action in response.

“I hope that the National Disciplinary Commission, which will meet on Wednesday, will be uncompromising,” he said.