Croatia's Ognjen Vukojevic vies with Cameroon's Pierre Achille Webo during their clash. A convicted match-fixer is alleged to have predicted the outcome of the game. Photo: Emmanuel Dunand

London – Two referees working at the World Cup have been identified as strong suspects in the fixing of international games, the Mail on Sunday can reveal.

Sources say Fifa were informed during the current tournament that there is evidence of alleged past malpractice by at least two officials on duty.

Fifa gather intelligence from associations and anti-corruption partners around the world on an ongoing basis. In recent times they have been swifter to act on intelligence than in the past. But it is understood that by the time the latest information filtered up to Fifa’s security hierarchy in Brazil, the two referees in question had already officiated matches.

The suspicions surrounding the officials are linked to historic games involving the “double whammy” identifiers of unusual in-game incidents matched with highly unusual betting.

Fifa responded to Mail on Sunday questions about the allegedly corrupt officials by saying: “It is important to note that we have no indications that the integrity of the Fifa World Cup has been compromised.”

There was no denial the information had been received or that it was considered serious.

“Generally speaking, we are not in a position to comment or provide information on any match-manipulation investigations that are ongoing so as not to compromise investigations, nor do we provide any comments as to whether or not any investigations are underway,” said a spokesman.

The tournament has already been rocked by allegations of fixing after German magazine Der Spiegel reported that convicted match-fixer Wilson Raj Perumal had told them before Cameroon’s group match with Croatia that Croatia would win 4-0 and Cameroon would have a man sent off. Perumal denies telling Der Spiegel this, saying he spoke to them after the match.

Fifa have publicly requested that Der Spiegel supply evidence of their claims, with Fifa director of security, Ralf Mutschke, saying “the allegations put the integrity of Fifa World Cup matches in question, which is a serious allegation”.

One source suggested to the Mail on Sunday that Der Spiegel may have been hoaxed by somebody on Facebook pretending to be Perumal. Der Spiegel has yet to hand any evidence to Fifa.

On the subject of the allegedly corrupt referees who have been working at Brazil 2014, a Fifa spokesman told the Mail on Sunday that any action taken against a corrupt party would become public only after such action had been sanctioned by various Fifa committees.

“It would be only after a decision has been taken by the Fifa disciplinary committee or Fifa ethics committee and first notified to the parties concerned that Fifa would be in a position to communicate the contents of that decision publicly,” said a spokesman.

Fifa continue to work closely with law enforcement agencies as well as the respective public authorities and other sports organisations on a national, regional and global level to tackle the issue of match manipulation.

“And we encourage that anyone with information about any suspicious matches should contact relevant authorities such as through FIFA’s integrity hotline or email address and confidential reporting system.” – Daily Mail, London