PARIS, July 14: France President Jacques Chirac on Friday called Zinedine Zidane's head-butt in the World Cup final ''unacceptable'', adding that something must have provoked it.

The French captain, playing his last match before retirement, was sent off for ramming his head into Italian defender Marco Materazzi's chest in Sunday's World Cup final in Berlin. Italy won in a penalty shootout.

''His gesture was not acceptable,'' Chirac said in a speech on France's national holiday, Bastille Day. ''That is obvious. He said so with great courage.''

Zidane apologized to children in a French television interview Wednesday, but said he did not regret the incident because Materazzi had insulted his mother and sister.

''What is certain is that, for a man like Zidane - a man balanced in all respects - to have this type of reaction, there had to be something,'' Chirac said.

The president said an investigation by world soccer body FIFA would show ''who is responsible and whether there was provocation.''

Chirac met Zidane on Monday at a team reception and called the French captain ''a virtuoso, a genius of world football.''

Materazzi has admitted insulting Zidane, but denied that he verbally attacked his mother. The Italian player appeared before a FIFA disciplinary committee on Friday. Zidane is scheduled to appear next Thursday.—AP