SINGAPORE - Gang arrests in Singapore has been on the decline over the last decade but police figures show gangsterism is still a problem.

Here's a look at three notorious gang heads.

Tan Chor Jin

Dubbed One-Eyed Dragon because he was blind in his right eye, the former Ang Soon Tong headman grabbed the headlines when he killed nightclub owner Lim Hock Soon execution-style in his home on Feb 15, 2006.

Tan, then 41, shot Mr Lim five times in front of his family before escaping to Malaysia. He was later arrested in Kuala Lumpur.

It was revealed in court that Tan and the deceased, believed to be from the Sio Gi Ho secret society, were partners in an illegal horse-racing and football betting venture.

Tan was later found guilty and hanged in 2009.

Roland Tan Tong Meng

The nation was reminded last year of its turbulent past with the death of Singaporean drug baron Roland Tan Tong Meng, who co-founded Ah Kong, an organised crime and drug syndicate originally based in Holland. It ruled the heroin trade in Europe from the 1970s to 1990s.

On the run from Singapore for 51 years, Tan, 72, died of a heart attack in his home in Copenhagen, Denmark, in April last year.

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Tan's funeral was attended by biker gangs Bandidos and Hell's Angels, with the police watching closely. His death received both tributes and condemnation online.

Tan was wanted in Singapore for the murder of Lam Cheng Siew. Mr Lam and nightclub singer Lim Kai Ho were attacked by armed men near Bras Basah Road in October 1969.

He was found dead in a nearby drain with stab wounds to his head and left arm. Tan, a suspect, escaped to Malaysia and later to Amsterdam.

Aw Teck Boon

Dubbed Singapore Siao - Madman of Singapore - Aw Teck Boon previously led a group of 60 men in the Sio Kun Tong secret society.

He was stabbed to death in Geylang by an unknown assailant in May 1999. Aw, who was 43, was known for his violent temper and his love for alcohol.

His tattooed body was found face down at the Eng Choon Wushu Association in Geylang Road, where he had apparently gone to sleep after having too much to drink at a Geylang coffee shop.

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There were no signs of a struggle but Aw suffered stab wounds on his neck, armpit and waist.

Some time in the early 1980s, Aw was arrested after he and some 100 gang members were embroiled in a fight with a rival gang, which resulted in the death of a man.

He had also spent time in prison under the Criminal Law (Temporary Provisions) Act for being a kingpin in the underworld.

This article was first published in The Straits Times. Permission required for reproduction.