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.
“There’s a real lack of adequate disclosure by the prosecution and that worries us about whether there will be a fair trial,” Hall, from the Migrant Worker Rights Network, told AFP before the judge confirming a decision on this 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.