If he is not given clemency, Nagaenthran Dharmalingam, a 34-year-old Malaysian who has an IQ of 69, will be put to death.

He was arrested in 2009 at the age of 21 with 43g of heroin, worth a few thousand dollars on the streets, as he entered Singapore. According to his lawyers, he had agreed to be a drug mule after a smuggler in Malaysia threatened him and his girlfriend.

He was found guilty in 2019 and sentenced to death, the mandatory sentence for drug trafficking in the jurisdiction. Exemptions may be given for the intellectually impaired.

“Nagaenthran should be protected from the death penalty because of his intellectual disability,” said Maya Foa, director of Reprieve. “Allowing this travesty of justice to take place would fly in the face of those promises.

“We urge President Halimah Yacob to listen to the cries for mercy within Singapore and around the world, from the United Nations to global business leaders, and spare the life of this vulnerable man.”

Amnesty International’s southeast Asia researcher, Rachel Chhoa-Howard, said: “We urge the Singapore government to refrain from reinstating the use of this cruel punishment.

“The government must act immediately to stop a grave travesty of justice from taking place and end its inhumane, shameful strategy of using the death penalty to address drug-related problems.”