Reuters/Reuters - Myanmar migrant workers Zaw Lin (R) and Win Zaw Htun arrive at the Koh Samui Provincial Court, in Koh Samui, Thailand, July 22, 2015. REUTERS/Chaiwat Subprasom

Defence lawyers in the trial of two Myanmar men accused of killing two British backpackers on a Thai resort island last year said on Wednesday they would focus on the reliability of crucial DNA evidence. British tourists Hannah Witheridge, 23, and David Miller, 24, were killed last September. Their bodies were found on a beach on Koh Tao, a Thai island in the Andaman Sea popular with backpackers and divers.

The killings drew outrage in Britain and raised questions about the competence of Thai police and the treatment of migrant labourers in Thailand. Following weeks of pressure on authorities to solve the crime, Thai police said in October that Myanmar workers Zaw Lin and Win Zaw Htun, both 22, had initially confessed to the killings. Both later retracted their statements, saying they had been tortured into confessing.

The murder trial, which began earlier this month, has been consumed by allegations of police incompetence and evidence mishandling by defence lawyers. Rights groups have also claimed the men are being used as scapegoats because of their status as foreign migrant workers in Thailand.