TEENAGER Muhammad Nasir Abdul Aziz, who killed his lover's husband, was ordered by the High Court on Tuesday to be detained at the President's pleasure, an indefinite jail sentence.

Muhammad Nasir Abdul Aziz, 17, pleaded guilty to the murder but was not given the death penalty because of his age. He was two months short of 17 when he stabbed Mr Manap Salip, 29, a disc jockey, to death outside his 16th storey flat at Block 74, Whampoa Drive, on July 1 last year.

In all, he stabbed Mr Manap nine times in the back and on his neck. He threw the knife into a canal next to the block after the killing before taking a taxi home.

The murder plot was hatched not long after Muhammad Nasir had an affair with Mr Manap's wife Aniza Essa, 24. He had met her at the Razcals Pub, where she worked as a waitress and hostess.

Last week, Aniza, now 25, admitted that she had manipulated the teenager into killing her husband to escape an unhappy marriage.

She was jailed for nine years on a reduced charge of abetting manslaughter. A psychiatrist found she had a mental disorder that reduced her responsibility for the crime.

The prosecution is appealing for a stiffer jail term.

In court on Tuesday, Muhammad Nasir's lawyer, Mr Subhas Anandan, called Aniza a 'manipulative monster' who played on the boy's emotions to make him kill her husband.

The teenager now feels nothing but anger towards Aniza. He even has thoughts and urges to hurt her physically, according to a psychiatric report submitted to the court.

He now believes that Aniza had betrayed him and had made use of him to get rid of her hubby.

He is remorseful for killing Mr Manap and has difficulty sleeping because he keeps seeing his victim's face.

The teenager, the younger of two sons, had been brought up by his paternal aunt after his mother left the family when he was two months old.

He went back to live with his father, who had since remarried, when he was 10.

He quit school when he was 15.

The report, prepared by Dr Parvathy Pathy of the Institute of Mental Health, also mentioned Muhammad Nasir's strong emotional attachment to Aniza and how he was afraid of losing her.