Zinedine Zidane tonight apologised for his "unpardonable" head-butt against Marco Materazzi in Sunday’s World Cup final, but he said he did not regret the act because the Italian player had insulted his mother and sister.

"It was an act that was not pardonable. I apologise to all the children who might have seen it. I tell always tell children that they should avoid doing such things," Zidane told Canal Plus television in his first explanation for the incident 10 minutes from the end of the game.

Talking calmly with a military fatigue jacket draped over his shoulders, he confirmed that Materazzi had insulted him in an exchange after he had grabbed Zidane’s shirt.

"He just put his hand onto my shirt and I told him to stop. I told him that if he wanted it I could give it to him at the end of the match. Then he said very harsh words to me and repeated them several times. I left but then I went back towards him and things went very fast."

Zidane refused to go into detail, but said: "They were very hard words which touched me to the quick. It was very serious. It was about my mother and my sister. That wounds. He repeated it three times...I am a man before anything else... I would have preferred getting a right hook in the face than to hear that," he said. He said that he felt bad knowing that "millions of kids saw it."

"I apologise, especially to educators and those who tell kids what to do and what not to do," said Zidane, who is the supreme role model for children from the poor housing estates where he and half the French team grew up.

He insisted, however, that he did not regret responding to the Italian’s insults. "I cannot say that I regret my act. I apologise to all concerned but to regret it would mean that he was right to say those things."

Zidane, 34, who retired from football on Sunday, said that it was understandable that Fifa was investigating the incident, but he insisted that Materazzi should be punished for instigating it. "The guilty one is the one who created the provocation," he said.

"I have had enough of the reaction always being punished."

"You cannot think for a moment that 10 minutes from the end of my career it gave me pleasure to do that."

Materazzi, who was knocked to the ground by the extra-time butt to the chest, has acknowledged that he insulted Zidane, but denied that he called him a terrorist or impugned his mother. "It was an insult of the kind you will hear dozens of times and that just slips out on the ground," Materazzi told an Italian newspaper.

Sepp Blatter, the Fifa president, gave warning that he could strip Zidane of his Golden Ball title - awarded to the World Cup’s best player after the final - if the disciplinary committee finds against him.

"I have ordered our disciplinary committee to open an enquiry...The presumption of innocence until proven otherwise is and remains a sacred principle," he said.

He noted that the Golden Ball was awarded on the basis of a vote by journalists, but added: "Fifa’s executive committee has the right and the duty to intervene when faced with behaviours that are against the ethic of sport."

Blatter said that Zidane refused to attend Sunday’s cup closing ceremony because he felt shame over his attack on Materazzi. Whatever FIFA’s reaction, Zidane has largely been forgiven by his own country since the shock and sadness from Sunday’s defeat has faded.

Zizou returned on Monday to a hero’s welcome from President Chirac, who said that he represented" all the most beautiful values of sport, the greatest human qualities. He is a man who has honoured ...France.

A poll in Le Parisien has found that 61 per cent of the country forgives the footballer and 52 percent say they sympathised with his violent reaction.

Zidane has received backing from children on the immigrant housing estates on which he and over half the French side grew up. It was understandable that he should defend his honour in the face of an insult, the argument goes. Materrazzi is the one who should be punished, they say.

This logic has spread among the intellectual classes who are now depicting Zidane’s gesture as an "existential act".

Le Nouvel Observateur, the leftwing news magazine, today hailed Zizou for putting his footballing reputation second to defending his honour.

"He showed that the World Cup is not the only thing that matters. That dignity is more important than sport and television glory. You do not swallow an insult for the shameful satisfaction of leaving the stadium under applause."

Bernard-Henri Levy, the most glamorous philosopher, gushed that Zizou remains a "man of providence, saviour, titan, valiant knight, a blue redeeming angel dressed in white" although he had shown, like Homer’s Achilles, that he possessed a fatal flaw -- a bad temper in his case.

Gilbert Collard, one of France’s most celebrated defence lawyers, today went as far as hailing Zidane’s head-butt as a noble gesture. "Of course it was wrong, but it was explained, if not justified, but honour."