Singapore on Wednesday executed a man who had been convicted of drug trafficking, despite appeals for clemency from his family, activists and the United Nations, Reuters reported.

Tangaraju Suppiah, 46, was arrested on charges of conspiring to traffic more than 1 kilogram of cannabis in 2014. He was convicted and sentenced to death in 2018.

Singapore has some of the world’s strictest anti-drug laws, according to the BBC. The city-state argues that they are necessary to prevent drug-related crimes, which is a significant issue in South-East Asian countries.

Last year, 11 persons were executed in Singapore for drug crimes. This included a disabled man who was convicted of trafficking three tablespoons of heroin.

On Wednesday, the United Nations Office for Human Rights had urged Singapore not to proceed with the execution and to “adopt a formal moratorium on executions for drug-related offences”.

Several human rights activists and organisations have questioned Singapore’s anti-drug laws. They also claimed that Suppiah’s conviction was based on weak evidence and that he had received limited legal access during his prosecution, according to the BBC.

Amnesty International said that Suppiah’s conviction relied mainly on the statements, which were recorded without a lawyer and interpreter, during his police interrogation and the testimony of two co-accused in the case, one of whom had his charges dismissed.

“In countries that have not yet abolished this punishment, international safeguards require that the death penalty be imposed only when the guilt of the person charged is based upon clear and convincing evidence leaving no room for an alternative explanation of the facts – and after a legal process which gives all possible safeguards to ensure a fair trial,” Amnesty International said.

British billionaire Richard Branson, a well-known opponent of capital punishment, claimed that Suppiah was not anywhere near the drugs at the time of his arrest.

However, Singapore’s foreign ministry refuted Branson’s allegation, saying that evidence suggested Suppiah was the person coordinating the delivery of drugs for the purpose of trafficking.

“Singapore’s policies on drugs and the death penalty are derived from our own experience,” the ministry said. “Our approach has worked for us, and we will continue charting our own path according to what is in the best interests of Singaporeans.”