Described by friends as an "average Joe".

Dropped out of secondary school.

Said to be an avid gambler, punting thousands of dollars at a time on horse racing and football.

Said to frequent casinos; friends described him as a high-roller.

Jailed for less than a year in 1990s for being an illegal horse-racing and football bookmaker.

Said to have fled Singapore in 1994 after losing $1.5 million betting on that year's World Cup. Returned after creditors agreed to let him pay off his debt in instalments.

Spent most of his free time watching television and monitoring the stock market. Ironically, he rarely watched football.

Convicted Singaporean match- fixer Wilson Raj Perumal is said to have supplied betting tips to Tan.

Invested in Perumal's now-defunct sports event promotion company Football Four U (later known as Exclusive Sports).

When Perumal wanted to buy a share of Finnish football club Tampere United, Tan invested around €300,000 (S$452,000) but withdrew it upon realising Perumal's plan to use the club ownership to manipulate the team's results.

Upon Perumal's subsequent arrest in Finland, he singled out Tan as the ringleader of a match-fixing syndicate, insisting that Tan instigated a certain Joseph Tan Xie to tip off the Finnish police.

Described by friends as loyal and that his "soft-heartedness" is his biggest weakness.

In December 2011, allegedly masterminded the fixing of matches in Italy's Serie A and B.

Charged in absentia by a Hungarian court in May 2013 for alleged role in fixing matches there.

Alleged to have manipulated 150 football matches in four continents.

Named by Interpol as "the leader of the world's most notorious match-fixing syndicate".

Arrested by the Singapore authorities in September 2013 along with 13 others.

Had been detained in prison since October 2013 under the Criminal Law (Temporary Provisions) Act. Released yesterday after detention was ruled unlawful.