Mothers of UK backpacker killers beg Thai king for sons' lives

The mothers of two men on death row in Thailand for the murders of two British backpackers have begged the country's king to spare their sons.

Wai Phyo and Zaw Lin, migrant workers from Myanmar, were sentenced to death in 2015 after being found guilty of murdering David Miller, 24, and murdering and raping Hannah Witheridge, 23 .

Their badly beaten bodies were discovered on a beach on the holiday island of Koh Tao in 2014.

Three court appeals attempting to overturn the death sentences have failed , so now the mothers of the convicted men have come to Bangkok to ask for a pardon from the king.

Speaking exclusively to Sky News ahead of submitting their petition, Phyu Shwe Nu, 55, and Taw May Thein, 52, maintained their sons are innocent.

"Don't kill my son," Phyu Shwe Nu sobbed. "My son didn't do it, my son didn't kill them. Please return them to us."

In August, Thailand's Supreme Court upheld the guilty verdicts - meaning the Thai monarch is now the only person who can overturn the death sentences.

Both men have consistently denied the murders, saying their original confessions were obtained under duress.

Their families claim they've been framed .

"My son said the Thai police caught them and beat them many times," Wai Phyo's mother Taw May Thein said.

"'Listen all of you,' the Thai police said, 'We'll burn you, chop you up, put you in a bag and throw it away'.

"Police forced my son. The boys were scared and confessed. He is innocent; why is this happening? After we heard our son's sentence, his father went crazy and passed away. Maybe I'll be next."

Police say evidence including DNA found at the scene and on Ms Witheridge's body led to Wai Phyo and Zaw Lin.

Police Colonel Kissana Phathanacharoen, deputy spokesman of Royal Thai Police, said: "We followed the legal procedure as to how we treated the offenders.

"We respected the principals of human rights and strictly follow the rules.

"They have all their rights guaranteed by Thai law. If there was any brutality or torture as claimed, they have the right to bring legal action against the Thai authorities. In five years they haven't done this."

The Supreme Court dismissed claims of physical mistreatment and mishandling of forensic evidence, saying the forensic work was done by respectable institutions and there was no proof of torture.

The family of Mr Miller has repeatedly expressed its view that justice has been done and the evidence against the men was overwhelming.

However, following the Supreme Court verdict, Mr Miller's father Ian said he hoped the death penalty would be withdrawn in exchange for prison sentences.

Zaw Lin and Wai Phyo's families will now submit a petition to the king asking that he commutes the death sentences to life in prison instead.

All death sentences in Thailand had been commuted by royal pardon in the nine years prior to a convicted murderer being executed by lethal injection in June last year.

Both mothers know this is their last chance and that the king could uphold the execution order at any time, but they refuse to abandon their sons.

"Every night I pray for him, it's all I can do," Taw May Thein cries.