Football's ruling body FIFA is investigating claims that over 300 matches on three continents were influenced by match-fixers, The Daily Telegraph reported on Friday.
FIFA suspects match officials were paid as little as $10,000 to help engineer specific results in international friendly matches and European club games, netting fixers hundreds of millions of dollars on Asian betting markets.
"The threat from match-fixing to the integrity of the global game is significant," Chris Eaton, FIFA's head of security, confirmed to the British newspaper.
"Interviews with those involved have told us that fixers can spend upwards of $300,000 to stage a friendly international and they do that with the expectation of a significant profit margin," the former Interpol official added.
Eaton told the Telegraph he believed fixers had made "tens of millions of dollars" in profit.
Employees from at least six different national football associations are under suspicion of assisting the criminal network, which is thought to work out of Singapore and Malaysia.
FIFA fear the upcoming under-17 and under-20 World Championships are at risk.
"We have admissions from those we are focusing on that they have been planning to target younger players at the under-17 and under-20 level," Eaton told the broadsheet.
"That is enough to make me concerned that we need to put preventative measures in place," he added.
Matches under suspicion include club games in Germany and Finland, Europa League fixtures and friendly internationals involving Kuwait, Jordan, Bolivia, Latvia, Bulgaria, Estonia, Malaysia and Zimbabwe.
A friendly game between Bahrain and Togo came to the world's attention after the African country denied sending a team, and were instead represented by amateurs who struggled to last the full game.
During the match, which is under investigation, Bahrain scored eight goals, five of which were ruled out, resulting in a 3-0 scoreline.