Police have charged a Brazilian footballer with attempted murder after he kicked a referee in the head.

Sao Paulo de Rio Grande’s William Ribeiro was playing in the second division against Guarani de Venancio when he attacked referee Rodrigo Crivellaro.

After a decision went against him, Ribeiro forced the official to the ground before savagely booting him in the head.

He had to be restrained by fellow players as the game was suspended and armed police arrived to arrest him.

Crivellaro was knocked unconscious and is thought to have suffered injuries to both his head and spine during the unsavoury attack.

After being discharged from hospital on Tuesday morning, he told reporters he has no recollection of the incident.

Sao Paulo de Rio Grande have immediately terminated Ribeiro's contract, labelling it one of the "saddest episodes in their history" and "unfortunate, regrettable and above all revolting".

President Delvid Goulart Pereira, speaking on their 123rd anniversary as a club said: "We are sorry and deeply ashamed.

"We send all the apologies in the world to the referee and his family as well as apologising to the public in general for the lamentable scene seen today."

A magistrate later confirmed that Ribeiro had been charged with attempted murder, which carries a maximum sentence in Brazil of 30 years in prison.

But it is not yet known if he will be released on bail or remain behind bars until his trial.

Local police investigator Vinicius Assuno told journalists: "His attack was very strong and violent, kicking the referee in the head and making him pass out.

"The referee had no chance of defending himself."

The match was eventually finished on Tuesday, with Sao Paulo losing the clash 1-0.