Singapore on Wednesday executed a 46-year-old Tamil man convicted of conspiracy to smuggle 1 kg of cannabis, ignoring pleas from the family, activists and the UN to reconsider capital punishment.

Tangaraju Suppiah was hanged at Changi Prison at dawn, the BBC reported quoting his family members.

A day before the execution, a Singapore court dismissed an application by Suppiah to have his case reviewed.

"The family said they weren't going to give up on him right until the end. It has been such a harrowing experience for them," anti-death penalty activist Kirsten Han told the BBC on Wednesday.

"They still have a lot of unresolved questions about his case, and the evidence against him."

Suppiah was convicted of abetting by engaging in a conspiracy to traffic 1,017.9 g of cannabis from Malaysia to Singapore in 2013, and sentenced to death in 2018.

The move came even as the UN Human Rights Office had asked Singapore on Tuesday to "urgently reconsider" the capital punishment.

Stating that Suppiah was convicted on weak evidence, anti-death penalty activists said he was not given adequate access to an interpreter and had to argue his last appeal on his own since his family was unable to secure a lawyer.

Slamming the execution, British billionaire Richard Branson said that Singapore "may be about to kill an innocent man" on the back of "more than dubious circumstances".

Singapore's Home Affairs Ministry said on Tuesday that Tangaraju's guilt had been proven beyond a reasonable doubt, adding that Branson's comments showed "disrespect" for Singapore's judges and criminal justice system.

Suppiah's execution was the first to be carried out by Singapore after a gap of six months.

The city-state, which has some of the world's toughest anti-drug laws, awarded 11 capital punishments in 2022.

The Singaporean government says that the death penalty is an effective deterrent against drug crimes and that it is widely supported by the public. (PB/NewsGram)