Allegations of match-fixing at the World Cup have been undermined by contradictory statements about the claims.
The allegations involving the Cameroon team, which strike at the heart of the World Cup's integrity, were made by German magazine Der Spiegel.
The magazine said it is sticking by its report, which stated convicted match-fixer Wilson Raj Perumal correctly predicted Cameroon's result against Croatia - a 4-0 defeat and that a player would be sent off in the first half - in a Facebook discussion with a journalist before the game.
Perumal, known as the Godfather of match-fixing, then issued a statement saying he made his remarks about Cameroon after the match.
The contradictory statements will serve to further muddy the waters of the ethics investigation launched by the Cameroon football federation (FECAFOOT) into three Group A matches, particularly the defeat to Croatia on June 18 in Manaus.
FIFA's security department is also believed to be looking into the claims.
FIFA president Sepp Blatter told Press Association Sport in Rio de Janeiro: "Yes, I have been told about this but let them do their work on this investigation."
Cameroon headed home from the World Cup after losing against Brazil and Mexico, as well as Croatia, to finish bottom of Group A.
Der Spiegel said not only was the scoreline correct, but Cameroon's Barcelona midfielder Alex Song was sent off before half-time for elbowing Croatia's Mario Mandzukic.
But Perumal said in a statement: "Contrary to the 'revelations' published by the German weekly Der Spiegel that were picked up by news outlets worldwide, I did not predict the result of the Cameroon vs Croatia match.
"The Facebook chat with the Der Spiegel journalist took place a few days after the match - June 21st, as confirmed by my Facebook log - and was but an informal assessment of the behaviour of the Cameroon team at the Brazil 2014 World Cup after they had played two of their three group stage matches, including the one with Croatia.
"At no time did I make reference to four goals being scored or to a red card being issued."
Der Spiegel did not issue the definite proof of any conversation but responded by saying: "We firmly stand by our assertion that Mr Perumal wrote in a Facebook chat with Der Spiegel some hours before the match Croatia vs Cameroon, that the result of the match will be a 4:0 victory for Croatia and that a player of Cameroon will get a red card in the first half."