Thai beach murders: Hannah Witheridge's sister criticises police

Hannah Witheridge, of Hemsby, Norfolk, was a postgraduate speech and language therapy student at Essex University

The sister of a Thai murder victim has criticised the police inquiry into the case and says she got death threats.

Hannah Witheridge, 23, from Norfolk and David Miller, 24, of Jersey, were killed on the island of Koh Tao.

Laura Witheridge said police "bungled" the investigation and had "nothing to tell us". She said she feels frightened after being sent defaced photographs from people in Thailand.

The Thai Embassy and Royal Thai Police have been asked to comment.

Burmese migrants Zaw Lin and Wai Phyo were last month convicted of the 2014 murders and sentenced to death.

Laura Witheridge made her comments in a public post on Facebook, which has since been shared more than 4,000 times, but has declined to speak to the BBC about the claims.

The family of David Miller - who was murdered with Hannah Witheridge - has said people should respect the court's verdict

It comes after the family of Isle of Wight bricklayer Luke Miller, found dead in Kao Tao last week, said it had concerns over the inquiry into his death.

Miss Witheridge said her family had been expecting a briefing when they travelled to Thailand soon after Hannah's death to collect her body, but were instead "ambushed by a mob of hungry journalists" at police headquarters.

"The Thai police chief had no intentions of giving us an update… after all, the bungled investigation meant he had nothing to tell us," she said.

She claims she has had "many death threats from Thai people" since her sister's murder, has been sent crime scene photographs and been chased in her car.

"They defaced photographs of me saying that the killers had only done 'half the job'… people commented on these photographs saying things like 'there is still time', and 'tick tock tick tock'.

Wai Phyo and Zaw Lin denied murdering the British pair

Miss Witheridge, who claims Thailand's "aesthetic beauty can lure you into a very dangerous trap", said she was now frightened of her own shadow and is constantly looking over her shoulder.

"I am exhausted, but frightened to sleep because of the nightmares. I miss my sister desperately," she said.

"My heart is heavy and my mind is tired."

Amnesty International has called for an independent inquiry over allegations Thai police tortured both defendants during the inquiry.

On their conviction in December Michael Miller, David's brother, urged those who had doubted the accused's guilt to respect the court's decision.