Thailand murder: Police officer casts doubt over DNA evidence
A Thai police officer in the Koh Tao murder case has cast doubt over whether DNA evidence from the suspects will be able to be re-tested.
Lieutenant Col Somsak Nurod told the BBC's Jonah Fisher that some of the samples exist in too small a quantity to be re-tested, while others have been lost.
Burmese migrants Zaw Lin and Wai Phyo, both 22, deny killing British tourists David Miller, 24, and Hannah Witheridge, 23.
Their bodies were found at a beach on the popular tourist island last September.