By Amy Sawitta Lefevre
BANGKOK (Reuters) - Two Myanmar men were charged on Thursday with the murder of two British tourists in Thailand, public prosecutors said, the latest turn in a roller-coaster case that has been blighted by allegations of a bungled investigation and ill treatment.
The bodies of Hannah Witheridge, 23, and David Miller, 24 were discovered on the southern holiday island of Koh Tao on Sept. 15. A post-mortem examination revealed that the pair died from blows to the head and that Witheridge had been raped.
The killings crippled tourism, which accounts for nearly 10 percent of Thai gross domestic product, and the investigation has raised serious questions over police tactics.
Thailand is under martial law following a May coup that saw the army seize power after months of political demonstrations, which had already kept some visitors away.
Myanmar workers Zaw Lin and Wai Phyo, both 21, were named as suspects in October. Police said the pair had confessed to the murders and that DNA samples found on Witheridge matched the suspects - despite the fact that the two had at the time yet to appear in court to face any charge and speak for themselves.
Wai Phyo was formerly identified as Win Zaw Htun.
Both later retracted their confessions, saying they had been beaten and threatened with electrocution - accusations police deny.
Last month, the suspects appealed to the victims' families and the British government for help. In a letter written in Burmese, the pair said they had nothing to do with the crime.
Rights groups, including Amnesty International, have expressed concerns about the police probe and called for an independent investigation into allegations of ill-treatment.
(Additional reporting by Kaweewit Kaewjinda and Juarawee Kittisilpa; Editing by)