BANGKOK (Reuters) - Thailand's human rights commission will launch an inquiry into allegations of police torture of two migrant workers from Myanmar arrested over the murders of two British tourists, the rights body said on Monday.
The investigation comes amid growing diplomatic concern that there may have been foul play during the police interrogation of the men. Thailand's police chief has denied the accusations.
"The commission will invite authorities involved in the investigation to meet next week to see if there is reason to suspect that they used force or tortured the suspects," National Human Rights Commissioner Niran Pitakwachara said.
"They told us they were tortured but we have not been able to confirm this yet," he added, referring to the suspects.
Britons Hannah Witheridge, 23, and David Miller, 24, were found dead on a beach on Thailand's southern island of Koh Tao on Sept. 15. Both had severe head injuries, an autopsy by Thai police found, and Witheridge was raped.
Two Myanmar men, identified as "Saw Rim" and "Win", both 21, were charged this month with the murder of both Britons and the rape of Witheridge after police said the pair had confessed to the killings and that DNA evidence from Witheridge matched samples taken from the two men.
The killings have hurt Thailand's vital tourism industry, which accounts for 10 percent of gross domestic product. The country is under martial law after a May coup and tourism is struggling to recover from months of political protests.
Police came under pressure to solve the case quickly, and critics have accused them of bungling the investigation. The men's arrest sparked fears they might have admitted to the murders under duress.
Rights group Amnesty International has urged the Thai government to conduct an independent investigation into torture accusations.
"From our initial investigation of the suspects we did not see wounds, but we did see a bruise mark on the chest of one of the suspects so we will ask that prison authorities x-ray the suspect's chest," said commisioner Niran.
Thailand's government has said it will allow British police to help investigate the murders but has not provided further details of what kind of assistance Britain would give.
"We have no problem with British police coming in to help investigate this case," deputy prime minister General Prawit Wongsuwan told reporters.
The British embassy in Bangkok did not immediately respond to a request for comment.
Reporting by Amy Sawitta Lefevre and Panarat Thepgumpanat; Editing by Clarence Fernandez