Two Myanmar migrant workers have retracted their confessions to killing two British travelers on a southern Thai resort island and now claim to have neither raped the female victim nor slain the pair, the men's lawyers said Wednesday.

Human rights lawyer Rasada Manurasada said the arrested men claimed they were tortured and forced to confess under police custody, allegations previously denied by the police.

Rasada said that Win Zaw Htun and Zaw Lin, both 21, have sent a retraction letter to prosecutors handling their case.

The battered bodies of Hannah Witheridge and David Miller were found on a beach on Koh Tao island on Sept. 15.

The crime damaged the image of Thailand's tourism industry, and its investigation has attracted concern the men might be scapegoats. Thai police have said they have DNA evidence linking the two men to the crime.

Concern that the men were tortured originated with advocates for migrant workers, who are often abused and mistreated without the safeguards of rights held by Thai citizens. But the allegations also have caught the attention of the British government, which expressed its concern earlier this month to a senior Thai diplomat in London.

Foreign Office minister Hugo Swire said he told Charge d'Affaires Nadhavathna Krishnamra that inquiries into the deaths should be "conducted in a fair and transparent way." Swire said it was vital the victims' families were kept updated, and expressed "concern about the way that the police had engaged with the media on the case." British officials were already upset that Thai media had published photos they believed violated the privacy of the victims and their families.

The Thai government declared that the diplomatic meeting was a consultation by mutual agreement, rather than a summon from the British side, which is indicative of a complaint.

London's police force announced Saturday that Scotland Yard detectives would travel to Thailand to help with the investigation.

British police said in a statement that officers would work with Thai police to ensure the killers were brought to justice in a clear and fair process.