LONDON (AFP) - Thailand's Prime Minister Prayuth Chan-O-Cha has agreed to allow the British police to help with the investigation into the murder of two young Britons on the holiday island of Koh Tao, diplomatic sources said on Friday.
The head of the junta dropped his objections to a visit by British detectives following a face-to-face meeting with British Prime Minister David Cameron on the margins of the Asem summit of European and Asian leaders in Milan.
"What the Prime Minister secured this morning was agreement from the Thai prime minister that we can send some British police investigators to Koh Tao to work with the Royal Thai Police on this," a British diplomatic source said.
Myanmar migrant workers Zaw Lin and Win Zaw Tun were charged with the murder of David Miller, 24, and the rape and murder of Hannah Witheridge, 23, after the tourists' battered bodies were found on Koh Tao on September 15.
Thai police have said the two suspects confessed to the crime and their DNA matched samples taken from Ms Witheridge's body, but there have been accusations that the men were tortured - something Thailand strongly denies.
"There are two areas we are particularly concerned about," said the diplomatic source.
"One is the verification of the DNA samples of the suspects, making sure there is further independent verification. And the second is the investigation into allegations of mistreatment of the suspects."
The source stressed that "obviously it is for the Thai authorities to lead and carry out that judicial process", but said it was important that it was "fair and transparent".
Britain summoned Thailand's top diplomat in London on Monday to lay out its "real concern" about the handling of the case and offer its support, while the British envoy in Bangkok also met top Thai officials to discuss the case.
The grisly murders on the normally tranquil Thai island delivered a fresh blow to the kingdom's image as a tourist haven after months of political protests that ended in May's army coup, when Mr Prayuth seized power.