The Human Rights Commission (Suhakam) has expressed regret that Singapore executed Malaysian Prabu Pathmanathan today.

In a statement, Suhakam chairperson Razali Ismail said Singapore was still engaging in an archaic practice which went against the right to life and the norms of a progressive society.

"We urge Singapore to move towards greater awareness and take action towards abolishing the death penalty," he said.

Razali said while Suhakam was aware that the death penalty was not prohibited by the International Covenant on Civil and Political Rights (ICCPR), this exemption was only for "very serious" offences.

"This has been affirmed multiple times by the UN Human Rights Committee and the interpretation is that drug offences do not fulfil the criteria of a serious offence," he said.

Prabu, 31, was sentenced to death after being found guilty of trafficking in 227.82g of diamorphine or heroin into the island state on Dec 31, 2014.

He was executed by hanging at the Changi Prison this morning after a clemency petition by his family and appeals by Putrajaya were rejected.

Last year, the previous BN administration removed the mandatory death penalty for drug offences in Malaysia.

The new government, meanwhile, has pledged to abolish the death penalty with all current death row prisoners having the sentences converted to life imprisonment.