In police custody since 2011, the Singaporean has been providing information to Europe's investigators about the murky world he was once an integral part of.
Match fixing: Wilson Raj Perumal 'holds the key to the Pandora's box'
Since his arrest in 2011, Perumal has been talking to police, prosecutors and journalists about the shadowy world of fixing football matches, in which he was an active participant, and the millions of dollars that can be made in betting on them.
The Singaporean was convicted in the Lapland District Court of bribing players in the Finnish league, forgery and trying to flee from officials guarding him, and was sentenced to two years in prison.
Perumal told the police that he could be in danger for betraying his former colleagues. But he also believes that his associates were the first to break the cardinal rule of criminals not cooperating with law enforcement.
"It's not in my nature to sing like a canary," he wrote in a letter from prison. "If I had been arrested under normal circumstances, I would have been back in Singapore to serve my time as a guest of the state with my mouth tightly shut."
European investigators and prosecutors say Perumal has provided an invaluable window into the realm of match fixing, which is corroding the world's most popular sport. They say he has revealed who organises some of the fixing in football and how money is made wagering on outcomes prearranged with players, referees and officials who have been bribed or threatened.
"He's not the only operating match fixer of this style or this size in the world, but he's the first to be really captured in the way he was and now to cooperate the way he is," said Chris Eaton, who was the head of security of Fifa at the time of Perumal's arrest.
"He put two and two together and realised he'd been traitored," Eaton said in an interview. "It took several days before he decided that it was in his best interests to cooperate."
Police from Italy investigating dozens of fixed Italian games and a prosecutor looking into 340 suspect games elsewhere in Europe both travelled to Finland to question Perumal as a witness.
One investigator on those trips said that Perumal provided "very good interviews", that he is still cooperating even after his release from prison in Finland, and that evidence he provided has checked out.
Another investigator said that Perumal alerted authorities to two fixes in progress - the matches, the referees - and that his information was "100 per cent" right in both cases. That investigator called Perumal "a massive help".
Both investigators spoke on condition of anonymity because they were not authorised to discuss their work publicly. Perumal declined a request for an interview.
In court filings, the Italian prosecutors described Perumal as their "primary source of evidence" on Tan Seet Eng, also known as Dan Tan, a Singaporean they allege is the leader of the syndicate that fixed matches in Italy.
Perumal detailed to authorities how the syndicate is structured, how it places bets, and how it moves bribe money around the world, they said.
Italian prosecutors have issued an arrest warrant for Tan and listed him as the No 1 suspect in their match-fixing investigation.
Tan could not be found in Singapore. Five phone numbers identified as his by Italian prosecutors were disconnected, and no one answered the door at an apartment the Italians listed as his address.
Perumal told Finnish police that the syndicate has six shareholders - including himself - from Singapore, Croatia, Bulgaria, Slovenia and Hungary, and he said they divide up income from gambling on fixed matches. The syndicate places bets mainly in China, Perumal said, according to a transcript of his May 18, 2011, police interview obtained by the Associated Press.
He said the group fixed "tens of matches around the world" - in Europe, Africa, the Middle East and the Americas - from 2008 to 2010. He estimated the group's total profits after expenses at "several millions of euros, maybe five or six million".
"Perumal is key, because he provides a view into how it all fit together," the Italian prosecutor Roberto Di Martino said.
Investigators said Perumal has a long history as a match fixer and a broad array of contacts in football.
He boasted in a letter from prison: "I can pick up the phone and call from Afghanistan to Zimbabwe."
When arrested, he had numbers stored in his telephone for people in 34 countries. He carried a business card with a Fifa logo that described him as "executive manager".
Perumal wrote from prison that he started fixing matches in Asia in the early 1990s.
"I grew up in a region where football betting and match fixing was a way of life. Gradually I developed the ability and the expertise to execute the job myself," he said.
He claimed to have paid off players in Syria and Africa and spoke of fixes in the US and in Bahrain, as well as games involving teams from North Korea, Kuwait, Zambia, Bolivia, Venezuela and Togo.
Zimbabwe linked him to widespread corruption and fixes involving its players and football association.
Perumal also is suspected of rigging games involving South Africa before the country hosted the 2010 World Cup. Fifa determined that Perumal's company, Football4U, was a front for his betting syndicate and infiltrated the South African Football Association.
In Finland, Perumal told police how he distributed bundles of cash - tens of thousands of dollars at a time - to corrupt Finnish league players, including a ?56,000 (Dh275,000) bribe handed over in a stadium lavatory in 2010.
In a prison letter, he lamented that "all corrupt players and officials are like whores who will walk with the highest bidder. There is no loyalty in this business".
But he felt no guilt about his role.
"I have had players thanking me for giving them this opportunity and telling me how much this money will change their lives," he wrote.
"The only people who get affected are the illegal bookmakers, and they dissolve their losses in the massive turnover of profits."
Perumal had been in and out of prison repeatedly in Singapore. In 2010, he was given a five-year sentence for injuring a police officer. He appealed but then skipped town. The Singapore police spokeswoman Chu Guat Chiew said that Perumal is still wanted in Singapore.
In his prison letters, Perumal said he lived unnoticed in London while on the run, jogging daily around Wembley Stadium and attending Premier League matches at the weekends. The handwritten prison letters were sent via Perumal's lawyer to a journalist, Zaihan Mohamed Yusof of the New Paper in Singapore.
If not for peculiar circumstances in Finland, Perumal might never have talked.
His arrest came on a tip from an informant, also Singaporean, who walked into a police station in Rovaniemi in northern Finland in February 2011 and told the duty officer that Perumal was in the country.
The police tracked down Perumal and put him under surveillance to be sure that they had the right man, said Eaton, who is now the director of integrity at the International Centre for Sport Security, a Qatar-backed group funding research into match fixing.
The police in Finland followed Perumal to a game and saw him in heated discussion with a player.
That piqued their curiosity and prompted them to contact football officials.
They, in turn, got word to Eaton at Fifa, who already had Perumal on his radar and immediately recognised the significance of the Finnish catch.
"It was like a bell went off, an alarm went off, in my office," Eaton said.
If the police had not tailed Perumal and had just picked him up and sent him home for travelling on a fake passport, they might never have realised he was fixing matches and he might never have decided to cooperate, Eaton said.
"It would have been virtually a blip instead of the explosion it really was," Eaton said.
Before his arrest, Perumal had been gambling heavily, built up debts and defrauded his syndicate by pocketing money meant to be used to fix matches, Eaton said. He said Perumal had also become too well known for Tan's liking.
Perumal "was on Facebook. He was on LinkedIn. He was on Twitter," Eaton said. "Perumal's attitude was, 'This makes me more valuable, more known by players, more known by the people I want to corrupt and influence'. Tan wanted him to be more discreet."
In a prison letter, Perumal alleged that the tip to Finnish police was an effort by his associates "to get rid of me".
"I knew I was set up the moment they stopped me," Perumal wrote.
"Seeking police assistance is a violation of code No 1 in any criminal business. Dan Tan broke this code and stirred the hornets' nest. And now he has to face the consequences," Perumal wrote in another letter. "I hold the key to the Pandora's box and I will not hesitate to unlock it."
Investigators say Perumal's decision to cooperate was also motivated by self-interest. As long as he remains useful to authorities in Europe, he delays the day he might be sent back to Singapore, where he faces a prison term and possibly vengeful former associates.
"He'd be in prison for five years and perhaps he wouldn't come out of that prison," Eaton said. "He progressively started giving information. Not at once, not in some great blurting splurge. He gave enough each time to ensure that he wasn't extradited, that he wasn't sent back to Singapore, to a point where he gave enough that they are now using him in other investigations.
"He has realised his only way forward is to become an informant and to cooperate, Eaton said. "But I still don't believe he's given anywhere near 100 per cent of the information."
After serving half of his two-year jail sentence in Finland, Perumal was sent to Hungary, which had a European arrest warrant out for him, said Jukka Lakkala, the detective chief inspector of the Finnish Bureau of Investigation.
Eaton said Perumal served as a "controlled informant" in Hungary, living in a safe house under police watch. "And no doubt he'll be in Italy, too," Eaton said.
In declining the Associated Press interview request, Perumal replied in an email that he did not want "to provide any more details".
"My life is now settled," he said, adding that he prefers that it "remains that way".
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