Its adviser N Surendran said his sources, which comprised former and current Singapore prison officers, were “impeccable”.

“They are whistleblowers with impeccable service records. Singapore’s response is a bare denial.

“Our claims are solidly documented and backed by evidence from whistleblowers. Calling it a stunt is a cheap attempt to distract the issue by Singapore,” he told FMT.

Earlier today, Singapore’s home ministry rejected LFL’s claims, saying they were an attention-seeking stunt by the group.

“LFL has been publishing various falsehoods to seek attention in hopes of getting Malaysian prisoners, who have been convicted of drug trafficking and sentenced to death in Singapore, off the death penalty,” it said in a statement.

On Jan 16, LFL – a vocal opponent of Singapore’s death penalty in the wake of a series of hangings carried out on Malaysians convicted of drug offences in the republic – claimed it received evidence of brutal execution methods by prison guards in the event the hanging procedure fails during an execution.

Surendran said whenever the rope breaks during a hanging, a prison officer would pull the rope around the neck of the prisoner towards him.

“Meanwhile, another prison officer will apply pressure by pulling the body in the opposite direction,” he said.

Saying the details were shared by a former executioner at Changi Prison, Surendran added that prison guards would kick the convict’s back “with great force in order to break it”, while ensuring there would be no tell-tale marks in case there is an autopsy.

But Singapore said the claims were “untrue, baseless and preposterous allegations”, adding that all judicial executions in the state were carried out in strict compliance with the law.

This included the presence of the prison chief, a medical doctor, as well as a coroner’s confirmation within 24 hours that the execution was carried out properly.

The rope used for judicial executions, it added, has never broken before.