A Thai policeman described the harrowing moments he discovered the bodies of two British holidaymakers on Koh Tao Island as the high-profile trial of two Myanmar migrants charged over their deaths opened Wednesday.
Zaw Lin and Win Zaw Tun have both pleaded not guilty to the murder last September of 24-year-old David Miller and the rape and murder of Hannah Witheridge, 23, in a case that has tarnished Thailand's reputation as a tourist haven.
The two men, who have been in custody on neighbouring Koh Samui since October, arrived at court in a prison van with their feet shackled. They face several charges -- including murder, rape and robbery -- and if found guilty could face the death penalty.
Family members of the two British backpackers were also present as the trial began and the prosecution questioned their first witness, a policeman who found the tourists' bruised and battered bodies.
The officer described the awful scene as he discovered the lifeless Miller "face down" on the shallow surf followed by the body of Witheridge further up the beach. Police have said she was raped as well as beaten.
Their murders, just a few hundred yards from the main tourist drag in Koh Tao, sent shockwaves across the sleepy idyll in the Gulf of Thailand immensely popular with backpackers and divers.
But the prosecution has been marred by allegations of a bungled investigation with the defence team claiming the migrants, who worked for low wages in the tourism trade, were scapegoated by an under-pressure police force. 
One of their key demands has been the opportunity to independently test controversial forensic evidence against their clients.
After the opening of the trial the judge said a decision on this would be made Thursday, according to an activist for a migrants group helping to fund the defence case, as journalists were asked to leave the small courtroom to make room for family members.
 - 'Bright future ended' - 
Earlier Wednesday the families of both victims released statements confirming they would attend the trial's opening at the imposing courthouse perched on a hill overlooking Samui's lush palm trees and white beaches.
"Just hours before he died David was talking to us with his usual enthusiasm, describing the beauty of Koh Tao and the friendliness of the Thai people," Miller's family said in their statement, adding that they hoped to "gain a better understanding" of how the young Brit died.
"Hannah was a beautiful person, inside and out, she brought a room alive just being there," the Witheridge family wrote in their statement.
"Her bright future was brutally ended leaving those who loved her broken with no answers."
Miller's parents and brother were present at court Wednesday as well as Witheridge's father and brother.
Both families have appealed for privacy from the press for the duration of the trial, which is expected to take place over 18 staggered days between now and September with a verdict due in October.
 - Flawed evidence? - 
The killings came as the country's vital tourism industry was beginning to recover from months of violent street protests that culminated in the May 2014 military coup.
The case also shone a light on Thailand's many underpaid and often exploited Myanmar migrant workers who fill the lucrative tourist sector.
The pair's defence team have long criticised the police investigation, claiming the crime scene was contaminated and that their clients were tortured into admitting guilt.
Both men retracted their initial confessions, saying they were coerced into making them. 
The defence team had also complained about not being given access to the forensic evidence, despite the court initially ruling in April that they could run their own independent tests.
Andy Hall, an activist for the Migrant Worker Rights Network helping to fund the pair's case, told AFP he felt "confident" the judge would "allow" the tests the defence team have been demanding for months.
"There's a real lack of adequate disclosure by the prosecution and that worries us about whether there will be a fair trial," Hall had said before the judge confirmed a decision on the matter would be reached Thursday.
The forensic material from the crime scene has been used by Thai police and prosecutors to insist they have charged the right men, saying it strongly points to the Myanmar pair as the perpetrators.
The victims' families have also previously said they have confidence in the case after British investigators reported back to them following a visit to Thailand late last year.
© AFP