FIFA has insisted that there has been no indication of any match-fixing situations at the World Cup following reports that it had been warned over Nigeria.
The world governing body issued a statement after BBC Two's Newsnight program reported that a UEFA investigator had warned FIFA before the tournament that the Nigeria team could be vulnerable to match-fixing.
FIFA has responded, saying no information provided by any informant relating to potential match-fixing at the tournament has had any substance.
The statement said: "FIFA and the Early Warning System (EWS) have a network of informants from which we receive information."
"Of course, as you may understand, we will not disclose the identity of the informants. What we can say is that at least until today no information provided by the informants to FIFA in relation to any potential match-fixing activities during the 2010 FIFA World Cup have proved to have any substance."
"Furthermore, we can also say that there is no indication whatsoever until today of any match-fixing situations during any of the matches of the 2010 FIFA World Cup."
Newsnight reports that a UEFA investigator in South Africa raised concerns on the morning of Nigeria's first match against Greece that the players were 'vulnerable to manipulation'.
He also alerted FIFA's new Early Warning System body, set up to look for signs of match-rigging, of his concerns over betting patterns. Nigeria took a 1-0 lead against Greece but had a player sent off and Greece ended up a 2-1 winner.
Rick Parry, who heads up the Government's sport's betting integrity panel, praised UEFA for the systems it has in place.
"This is something they take extremely seriously," he told Newsnight. "They have a very successful warning system."
"FIFA have their own early-warning system. It's a robust system - it's the one the International Olympic Committee actually uses."
"But UEFA has been on the case for a long time because they've had concerns about eastern Europe."
"I think UEFA are to be commended for once for not being complacent and trying to grasp this by the scruff of the neck."
He added that there was no evidence to suggest any serious problem with match-fixing in this country.
"We can't be certain but the good thing is UEFA are monitoring games right across Europe, and there is absolutely no evidence that I've seen that there is a significant problem in England," he said.
"The game at the top in this country is as far as we know clean."