British backpacker Hannah was '˜unlawfully killed' rules inquest

Hannah Witheridge, 23, from Hemsby, Norfolk, and Leeds University graduate David Miller, 24, from Jersey, were found dead on the island of Koh Tao on September 15 2014.

Burmese migrants Zaw Lin and Wai Phyo have since been sentenced to death after being found guilty of murder.

They are appealing against the verdict saying they were tortured and forced to confess and that evidence against them was tampered with.

An inquest into Miss Witheridge’s death was held at Norwich Coroner’s Court on Monday morning.

Norfolk coroner Jacqueline Lake heard that her death was caused by “severe head injuries”.

She recorded the conclusion that Miss Witheridge was unlawfully killed.

Post-mortem examinations showed that the young backpackers, who had met on the island while staying at the same hotel, both suffered head wounds and that Miss Witheridge had been raped.

During a trial last year, prosecutors claimed DNA evidence collected from cigarette butts, a condom and the bodies of the victims linked Lin and Phyo to the killings.

But lawyers representing the pair, both 22, said DNA samples from the alleged murder weapon – a garden hoe – did not match that of the two men.

The defence team said DNA evidence was mishandled by police and the defendants’ confessions were a result of torture in the context of “systematic abuse” of migrants on Koh Tao.

A bizarre reenactment of the murders in which the defendants were paraded in front of the media was also “staged under threat of violence”, the lawyers added.

Thai police denied using force during their investigation.

Campaign group Amnesty International has called for the murder case to be investigated.

They say Thai authorities should launch an independent examination into claims by the pair that police tortured them - including by stripping, beating, kicking and issuing threats of electric shocks - to extract “confessions”.

In its own investigation of the case, the Thai National Human Rights Commission found the allegations of torture by the two men to be credible.