Singapore police said they needed hard evidence to crack down on match-fixing cartels, after coming under pressure to arrest suspected ringleaders of networks which targeted hundreds of football games in Europe and beyond.
Police said authorities had supplied information about Dan Tan Seet Eng, a key suspect who is wanted by investigators in Rome, and that they were working with Europol following revelations that Singapore-linked networks rigged or tried to rig 680 games worldwide.
"The authorities in Singapore are assisting the Italian authorities through Interpol in their investigations into an international match-fixing syndicate that purportedly involves a Singaporean, Dan Tan Seet Eng," police told AFP in an email.
In a separate statement, police said they were seeking more information from Europol, which detailed its findings this week after a major investigation, and that they were working with authorities in several countries.
"Syndicated match-fixing is a complex global problem that can only be effectively eradicated if all countries work together to combat the scourge," the Singapore police said.
"This requires law enforcement agencies to proactively share information and intelligence so that concrete evidence can be gathered to support enforcement actions on the ground."
Europol said some 380 of the games were in Europe, and included Champions League ties, World Cup and European Championship qualifiers, and top-flight fixtures from around the continent, linking the conspiracy to ringleaders in Singapore.
Dan Tan is the subject of an Italian arrest warrant and reports say he has been accused in German court documents, and named in investigations in several countries. He is suspected of being one of about five Singaporean ringleaders.
Singapore has come under pressure to explain why key suspects such as Dan Tan remain at large, with Interpol secretary Ronald Noble telling the Straits Times newspaper that the small, wealthy country's "reputation would continue to suffer" until arrests are made.
Singapore has long been considered at the heart of international football match-rigging after fixers learned their trade in the local and Malaysian league before venturing into Europe in the 1990s.
According to reports and investigators, they provide money to local operators to fix games, and then place clandestine bets on Internet gambling sites, mainly based in Asia, with potential winnings running to millions of dollars.
Singapore's Wilson Raj Perumal, who claims to be an ex-associate of Dan Tan, is believed to have been a key informant for the European probe and the cracking of Italy's "calcioscommesse" scandal following his arrest in Finland in 2011.
Interpol told AFP its match-fixing task force currently has 28 members working in Singapore, which is also the site of a new Asian base for the global police body.
With so much activity going on for so long, some observers are wondering how key suspects remain at large in Singapore.
"A question that really must be asked is why so little is being done to question Singaporean individuals allegedly involved in such a global match-fixing operation," Neil Humphreys, a Singapore-based football commentator, told AFP.
"More pertinently, the issue has not received quite the same front-page media attention that it has in other football-popular countries, despite the obvious fact that Singapore is allegedly home to the ringleaders of the world's biggest match-fixing syndicate."
Humphreys is the author of "Match Fixer", a fictional work about a former striker for an English football team who tries to salvage his career in Singapore, only to plunge into a world of vice.
The latest match-fixing revelations come at a troubling time for sport, after Lance Armstrong confessed to drug-cheating his way to his seven Tour de France titles. On Thursday, Australia revealed doping was widespread among its athletes.