Singapore (AFP) - Singapore hanged a prisoner on Wednesday after he was convicted of conspiracy to smuggle one kilogram of cannabis, despite rights groups decrying “many flaws” in the case.

Tangaraju Suppiah was hanged in defiance of a plea by the United Nations Human Rights Office for Singapore to “urgently reconsider” and calls by British tycoon Richard Branson to halt it.

The Asian financial hub has some of the world’s toughest anti-narcotics laws and insists the death penalty remains an effective deterrent against trafficking.

“Singaporean Tangaraju Suppiah, 46, had his capital sentence carried out today at Changi Prison Complex,” a spokesman for the Singapore Prison Service told AFP.

Tangaraju was convicted in 2017 of “abetting by engaging in a conspiracy to traffic” 1,017.9 grams (35.9 ounces) of cannabis, twice the minimum volume required for a death sentence in Singapore, the spokesman said.

He was sentenced to death in 2018 with the Court of Appeal later upholding the decision, but rights groups have claimed there were several problems with the case.

Human Rights Watch deputy Asia director Phil Robertson said the evidence “was far from clear cut – since he never actually touched the marijuana in question, was questioned by police without a lawyer, and denied access to a Tamil interpreter when he asked for one.”

He added the hanging “raises serious concerns that Singapore is launching a renewed spree to empty its death row in a misguided effort of deterrence.”

Amnesty International Deputy Regional Director Ming Yu Hah said there were “many flaws” in the case and that the hanging showed “the staggering failure of Singapore’s stubborn embrace of the death penalty.”

- ‘Not anywhere near’ drugs -

Singapore authorities have maintained that Tangaraju was given due process and that his guilt had been proven beyond a reasonable doubt.

The Ministry of Home Affairs said “the evidence clearly showed that he was the person coordinating the delivery of drugs, for the purpose of trafficking.”

Branson, a member of the Geneva-based Global Commission on Drug Policy, wrote Monday on his blog that Tangaraju was “not anywhere near” the drugs at the time of his arrest and that Singapore may be about to put an innocent man to death.

On Tuesday, the ministry slammed Branson, saying that the billionaire showed “disrespect for Singapore’s judges and our criminal justice system with such allegations.”

In some parts of the world – including neighbouring Thailand – cannabis has been decriminalised, with authorities abandoning prison sentences.

Rights groups have been heaping pressure on Singapore to abolish capital punishment, and the United Nations has said the practice has not proven to be an effective deterrent globally and is incompatible with international human rights law.

Singapore resumed executions in March 2022 after a hiatus of more than two years. Wednesday’s hanging was the city-state’s first in six months and 12th since last year.

Among those hanged was Nagaenthran K. Dharmalingam, whose execution sparked a global outcry, including from the United Nations and Branson, because he was deemed to have a mental disability.