File photo: AFP

Singapore -

An ex-gangster has been jailed for 20 years in Singapore for burning his former lover to death, in a case the judge said was one of the worst of its kind in the city-state.

Lim Ghim Peow, 45, was given the lengthy prison term on Monday after he pleaded guilty to setting his former lover ablaze.

“The accused in this case had torched a living human being immediately after dousing her with flammable petrol,” Judicial Commissioner Tan Siong Thye said in a written judgement sent to AFP on Tuesday.

“She was set ablaze screaming as a result of the excruciating pain from the burns.”

Mary Yoong Mei Ling, 43, died within hours after she sustained burns on 75 percent of her body in the incident on May 25, 2012.

Lim was tried on the lesser charge of “culpable homicide not amounting to murder” rather than murder, because a mental health check found he suffered from a “major depressive disorder”.

The maximum penalty for this is life imprisonment or a jail term of 20 years, as well as a fine and caning.

The judge said “this would have been a clear case of murder if it had not been for his major depressive disorder”.

Lim had been in a three-year relationship with Yoong, but this ended in 2011 after he physically abused her.

According to court documents, Lim had staked out Yoong's home from the early hours that same day in May 2012.

He then confronted her when she left her apartment in the morning, and demanded that she reconcile with him.

When she refused and asked him to leave, he doused her with a bottle of petrol and used a lighter to set her on fire.

The judge described it as a “very cruel and vicious attack” and “one of the worst cases” of its kind the High Court had seen.

He also noted that Lim had carefully planned the assault. He also had a “latent violent disposition” as well as a history of being involved in local criminal gangs.

“Therefore, considering the heinousness of the (crime) and the need to prevent further acts of violence, a very long sentence of imprisonment is warranted despite the accused's major depressive disorder,” the judge said.

Singapore, a regional financial centre and one of Asia's richest and safest cities, takes a tough stand against crime.

The city-state's crime rate of 581 per 100 000 people in 2012 was the lowest in two decades. - Sapa-AFP