BANGKOK (Reuters) - A Thai appeal court upheld the death sentence handed down to two Myanmar migrant workers for the murder of two British backpackers on a holiday island in 2014, the two men’s lawyer said on Wednesday.

The bodies of backpackers Hannah Witheridge and David Miller were found on a beach on Koh Tao island in September 2014. Police said Witheridge, 23, had been raped and bludgeoned to death and Miller, 24, had suffered blows to his head.

Thailand sentenced Myanmar migrant workers Zaw Lin and Win Zaw Htun to death after convicting them of the crime on Dec. 24 2015.

A team of lawyers filed an appeal in May last year against the verdict. The 198-page appeal said that DNA evidence used in the case was inadmissible and had not been collected, tested, analyzed or reported in accordance with internationally accepted standards.

“The appeal court upheld the death sentence for the two defendants,” Nakhon Chompuchat, the defense team’s head lawyer, told Reuters.

The defense has 30 days to make another appeal to the supreme court.

The 2015 verdict followed an investigation and trial that were mired in controversy, including allegations of police incompetence, mishandling of evidence and torture of the suspects.

Thai police drew widespread domestic and international criticism for their handling of the case and the evidence. Protests erupted in neighboring Myanmar after the verdict, with many people there believing the two workers were scapegoats.