AP Sports Writer
PARIS (AP) -- When police arrested Wilson Raj Perumal in Finland, it didn't take long for him to realize that his criminal buddies had ratted him out.
He's been exacting revenge ever since -- by ratting on them, too.
Since his arrest in 2011, Perumal has been talking to police, prosecutors and journalists about the shadowy world of fixing soccer matches, in which he was an active participant, and the millions of dollars that can be made in betting on them.
EDITOR'S NOTE: This story is part of a months-long, multiformat AP examination of how organized crime is corrupting soccer through match-fixing, running over four days this week.
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 police that he could be in danger for betraying his former colleagues. But Perumal also reasoned that by fingering him to the Finns, his associates broke 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 jail. "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-rigging, which is corroding the world's most popular sport. They say he has revealed who organizes some of the fixing in football, as the sport is known in most countries, 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 head of security of FIFA, soccer's governing body, at the time of Perumal's arrest.
"He put two and two together and realized he'd been traitored," Eaton said in an interview with The Associated Press. "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 traveled to Finland to question Perumal as a witness.
One investigator on those trips told the AP 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 told AP that Perumal alerted authorities to two fixes in progress -- the matches, the referees -- and that his information was "100 percent" right in both cases. That investigator called Perumal "a massive help."
Both investigators spoke on condition of anonymity because they were not authorized to discuss their work publicly. Perumal declined an AP request for an interview.
In court filings, 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. Prosecutor Roberto Di Martino told the AP there are about 150 people under investigation, including Tan, but none of them has been indicted.
AP could not contact Tan 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 AP.
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 5-6 million."