Lawyers for Liberty adviser N Surendran said the Singapore Prison Service' claim that P Pannir Selvam, who is on death row in Changi prison for a drug offence, did not write a series of letters that have been circulated to the media is "blatantly false".

In a statement today, Surendran, who is acting for Pannir's family, also questioned if Pannir was being threatened.

The lawyer's statement came after the Singapore Prisons Service said Pannir had personally denied writing the letters detailing his days in prison ahead of his execution.

"Why would he do that when in fact he did write them and copies of his handwritten versions exist?

"Obviously, he would only have done so if he had been subjected to threats or other unlawful means of compulsion by the Singapore authorities.

"We are now deeply concerned about Pannir's safety and well-being. Has he been threatened, intimidated, assaulted or otherwise compelled by Singapore authorities to deny that he wrote those letters? Is Pannir now safe in Singapore Prison custody?" he said.

Surendran (photo, 2nd left) stressed that all leaders that have been published were written by Pannir himself.

"As proof of this, Pannir's family is in possession of the handwritten copies of the letters which were written by Pannir in prison.

"Further, the copies of Pannir's handwritten letters were also put up in the official website to save Pannir, www.savepannir.info.

"In short, anyone can see by looking at the copies on the website that Pannir did write the letters," he said.

Surendran said it was "highly irresponsible" for Singapore to make such a serious accusation without proper probing.

"This has only increased the anguish and suffering of the family who is desperately trying to save Pannir's life by engaging public support for their cause.

"It is quite clear from Singapore's wild claim of an 'orchestrated campaign against the Singapore government' that they want to intimidate and shut down the public campaign for Pannir in Malaysia and worldwide.

"Singapore's conduct shows that it wants to hang this Malaysian citizen quietly in the near future and does not want public attention drawn to his case," he said.

Surendran urged the Singapore government to reveal whether Pannir was threatened into denying that he wrote the letters and to guarantee his safety in prison.

He also asked the Singapore government to stop any efforts to silence the "Save Pannir" campaign.

"We further urge the Malaysian government to intervene in this matter which involves the safety of a Malaysian citizen abroad and seek necessary explanations and assurances from Singapore," he said.

Yesterday, the Singapore Prisons Service claimed the letters by Pannir were being written by someone else and that it was a campaign to pressure the Singapore government.

The Save Pannir campaign is seeking for the 32-year-old's life to be spared.

Pannir was sentenced to death after being convicted of trafficking 51.84g of heroin in 2017.

He was to be hanged on May 24 but was granted a last-minute stay after an appeal.

The Malaysian government has appealed for clemency for Pannir.