We all know from watching courtroom dramas that evidence that is unlawfully obtained is not admissible. The basic legal principle is that the police can use only certain means to gather evidence. If they obtain it in an unlawful way, however compelling it may be, it cannot be considered in court.

Two French organisations, World Cup Justice 2006 and the National Collective for Truth on the Final of the 2006 World Cup, are taking legal action against Fifa and the French football federation, based on that principle.

The groups are suing in an attempt to force an inquiry into the circumstances behind the sending-off of Zinédine Zidane for his head-butt on Marco Materazzi, the Italy defender, in the World Cup final. Their claim is based not on whether or not the France captain assaulted Materazzi, nor what Materazzi might have said to provoke him. Rather, they argue that Hector Elizondo, the Argentine referee, relied on video evidence relayed by the fourth official.

And, because Fifa does not sanction the use of video evidence during football matches, that evidence should not have been considered. Which means that Zidane should not have been sent off and the result of the World Cup final ought to be struck off.

Mehana Mouhou, the lawyer representing the plaintiffs, argues that Elizondo did not witness the incident. This appears to be the case from the television pictures. Zidane headbutted Materazzi near the edge of the Italy penalty area, while the ball was in France’s half of the pitch. The referee’s back was turned and at least one of his assistants was not looking.

Elizondo halted play some 25 seconds later, responding to frantic signals from the fourth official, Luis Medina Cantalejo, from Spain. Television pictures show Elizondo signalling for the Italy physiotherapists and doing his best to calm the situation. It appears that at this stage he had no clue what had happened.

One man who saw the incident was Gianluigi Buffon, the Italy goalkeeper. The video shows him gesturing to Dario García, an assistant referee, and pointing to his eye, as if to say: “You saw what happened — do something.” By the time Elizondo runs to the touchline to consult his assistant, 1min 45sec has elapsed. The pair talk for a few seconds and then the match official shows Zidane the red card.

“But this sending-off would only be valid if the fourth official, who initally brought the incident to the referee’s attention, had personally witnessed the head-butt,” Mouhou said. “Yet this does not appear to be the case. If he had seen it personally, he would have immediately notified the referee. But it is indisputable that this did not happen.”

The plaintiffs further allege that the fourth official, realising that something serious had happened (but not knowing what), must have turned to the television monitor at pitchside and seen the replay. Fifty-seven seconds passed between the replay and Elizondo’s consultation with García, plenty of time for the fourth official to tell the assistant what he saw.

Lawyers for Fifa and the French federation dismissed the lawsuit as a publicity stunt. It has little chance of success when it goes before a judge next Monday, but the issue raised is real.

It is hard to argue that video replays were not used in Zidane’s sending-off. The opportunity and, frankly, the necessity to use them were there. Had Zidane not been sent off and gone on to score the winning goal, it would have been a public relations disaster for Fifa.

If video evidence was used, Fifa owes the world an explanation. The fact that the decision to send off Zidane was correct does not minimise the implications. If it was used in football’s biggest game, the sport’s world governing body is not only contradicting itself, it is also setting a dangerous precedent. Employing video evidence selectively is deeply unsatisfactory. If it is to be used, it needs to be given strict guidelines. It cannot happen on the whims of a fourth official, a cameraman and a television director.

As World Cup footballing mysteries go, this one is up there with Geoff Hurst’s goal at Wembley in 1966. We can get to the bottom of what happened in Berlin. The question is whether anybody wants to find out the truth.

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