Image copyright Family photos Image caption The police investigation into the murders of Hannah Witheridge and David Miller has been widely criticised

Two Burmese men accused of killing two British tourists on the Thai island of Koh Tao have retracted their confessions, their lawyers have said.

The pair now say they did not commit the murders and did not see what happened, according to their lawyers.

The bodies of David Miller, 24, from Jersey, and Hannah Witheridge, 23, from Norfolk, were found last month.

The UK has expressed concern about the investigation - but Thai police say they have a "perfect" case.

Thailand's National Human Rights Commission said on Monday that it had found evidence that the two suspects, Zaw Lin and Win Zaw Htun, both 21, were physically abused by the police.

Both are migrant workers from Myanmar, also known as Burma, and were named as suspects in the weeks following the discovery of the two tourists' bodies on a beach on 15 September.

Image copyright EPA Image caption Zaw Lin (left) and Win Zaw Htun are seen here leaving Koh Samui provincial court

The men are charged with conspiracy to murder, conspiracy to rape, and robbery, and could face the death penalty if found guilty.

Defence lawyers for the men were provided by a migrant worker support group in Thailand.

Post-mortem examinations found Mr Miller died from drowning and a blow to the head, while Ms Witheridge died from head wounds.

'Scapegoats'

The investigation into their deaths has been widely criticised and over the weekend it was announced that police from the UK would be flying out to assist with the investigation.

Last week the Foreign Office summoned the Thai charge d'affaires to express concern about how the case was progressing.

Criticism has been voiced about the failure to seal off the crime scene after the killings, and about an early police claim that no Thai person could have committed such an act.

The mother of one of the suspects has said they are being made scapegoats by the Thai police for the murders.

Mr Zaw's mother, Phyu Shwe Nu, said the case against her son had been fixed.

Police say DNA found on Ms Witheridge matches samples taken from the men.

Koh Tao