Singapore authorities last year placed leaders of a global match-fixing ring operating from the city-state in indefinite detention after uncovering plans to rig the World Cup, according to a book released Monday. Zaihan Mohamed Yusof, a Singaporean investigative journalist who has reported extensively on football match-fixing, details how he learnt of the now-crippled gang's plans from government officials and a prominent sports corruption investigator.

"The syndicate had been posturing, setting up a base of corrupt football players and officials through matches played overseas in national leagues and international friendlies," Zaihan quoted one senior unnamed Singapore official as saying in "Foul! The Inside Story of Singapore Match Fixers". "When the 2014 World Cup comes, all they will be doing is collecting (their betting earnings)," the official said of the tournament which kicked off in Brazil last week, according to the book.

"Something had to be done to stop them... We couldn't take the chance," another official was quoted as saying. Zaihan also quoted Michael Pride, head of operations at Australia-based match-fixing investigators SI Sports Intelligence, as saying "this syndicate allegedly sets up fixes six months ahead of major matches".

"From source information, they were allegedly gearing up for the World Cup," Pride said. Singapore's police and anti-corruption agency in September last year rounded up 14 alleged members of a global match-fixing syndicate, in one of the biggest crackdowns yet on corruption in football. Authorities subsequently used a special law that allows indefinite detention to hold four key ring leaders of the group, including alleged kingpin Dan Tan, also known as Tan Seet Eng. Officials say the indefinite detention -- under a law typically used against gangsters -- is necessary because witnesses fear reprisals if they testify in court.

Speaking at the book's launch on Monday, Zaihan said the arrests last year had not deterred other Singapore-based fixers from rigging games. "I can assure you that some things may have changed, but nothing has stopped. Attempts are still going on," he said. He cited audio recordings he had received recently implicating an unnamed "prominent Singaporean and a known match-fixer in the Indonesian football league". Tan, a reclusive Singaporean businessman, first came to prominence when fixer Wilson Raj Perumal, also a Singaporean, was arrested and jailed in Finland in 2011 for rigging top-tier games there. Perumal told prosecutors in Finland he was a double-crossed associate of Tan, who has also been named in several European match-fixing investigations.

Tan protested his innocence in a rare media interview in 2011 and said he was mystified about why he had been branded as a match-fixer. In the book, Zaihan said Tan was living a "fairly visible lifestyle" in early 2013, even after he became known in the media as an alleged match-fixing mastermind. The journalist recalled watching Tan, believed to be 50 years old, play a match for a local amateur side called Oxley City.

"For a fleeting 15 minutes, he came on the pitch and played as though he were a star striker. Tan's love for the beautiful game was apparent," Zaihan wrote. Interviews with Tan's associates revealed he learned the trade in the early 1990s as an understudy to a veteran match-fixer, said Zaihan, a journalist with Singapore's The New Paper.

Ironically, Tan was nicknamed "Ah Blur" by associates, a colloquial term used in Singapore to refer to people who are slow to catch on. Zaihan's book comes after the April release of a tell-all e-book by Perumal, ghostwritten by Italian investigative journalism website "Invisible Dog". Perumal claimed in the book that he influenced football games at the Beijing Olympics in 2008 and the Atlanta Olympics in 1996.

Interpol has said that the ring busted in Singapore was the world's "largest and most aggressive match-fixing syndicate, with tentacles reaching every continent". Experts have said that easy international transport, a passport accepted around the world and fluency in English and Mandarin have helped Singaporean fixers spread their influence abroad with the support of external investors, most believed to be from China. The Doha-based watchdog International Centre for Sport Security warned in a May report that Asian-dominated criminal groups are laundering more than $140 billion in illegal sports betting annually.