BANGKOK (Reuters) - Independent forensics tests on a garden hoe Thai police believe was used to kill two British backpackers on a holiday island show no matches to the DNA of two Myanmar migrant workers accused of their murder, their lawyer said on Friday.
The killings last year of Hannah Witheridge, 23, and David Miller, 24, raised questions about Thailand's safety for tourists, the competence of its police and its treatment of migrant workers.
Lawyers for the accused Myanmar men, Zaw Lin and Win Zaw Htun, both 22, have made alleged police incompetence and mishandling of evidence central to their defense and sought help from Thailand's foremost forensics expert, Pornthip Rojanasunand, to scrutinize evidence.
Defense lawyer Nakhon Chompuchart said the court on Friday heard testimony from Pornthip's team confirming DNA was found on the hoe police said was the murder weapon, but it did not match that of his clients, or Maung Maung, a friend of the accused and a prosecution witness.
"(Pornthip's institute) compared the DNA samples obtained from police of both the suspects and Maung Maung. There was no match," Nakhon said outside the court on Koh Samui, a neighboring island to Koh Tao, where the Britons were killed.
Police have given conflicting statements about the DNA, saying some was lost or "used up", then later denying that and saying the DNA samples were accounted for.
The court in July ordered a reexamination of the police evidence by the justice ministry's central forensic institute, led by Pornthip, who has clashed with police numerous times before when her examinations exposed flaws in their cases.
The bodies of Miller and Witheridge were found a year ago on a beach on Koh Tao, a small island in the Gulf of Thailand popular with backpackers and divers.
Post-mortem examinations showed both suffered severe head wounds and Witheridge was raped.
Police said in October the accused men had admitted to killing the backpackers. But they later retracted their confessions saying they had made under duress.
The case continues.
(Writing by Martin Petty; Editing by Robert Birsel)