Ko Kama, a Muslim from Burma’s Rohingya province, is expected to come under cross-examination from the defence team over allegations he beat Burmese defendants Zaw Lin and Wai Phyo, who are both Buddhists.
The migrants are accused of murdering Islander David Miller (24) and 23-year-old Hannah Witheridge from Norfolk on the island of Koh Tao last September.
Defence lawyers claim that due to cultural conflicts between the defendants and the translator they were treated unfairly and subjected to serious assaults.
The court was also due to hear testimony from a doctor who examined Zaw Lin following his arrest and subsequent detainment.
A lawyer who was called by police to observe the formal questioning of the defendants was also due to give evidence.
Yesterday the defendants had new DNA swabs taken in an effort to prove their innocence.
The court heard testimony from two arresting police officers as well as another officer who took DNA samples from one of the suspects.
However, he admitted to the court that he was not a forensics expert but a bomb disposal officer who had only ever taken DNA samples in training.
Meanwhile, the two arresting police officers described how Wai Phyo was arrested on a ferry a couple of weeks after the murders while allegedly trying to flee the island.
He was found hiding on the boat when it docked. But the officer admitted, under cross-examination, that the defendant may have simply been trying to evade arrest for not having the correct documentation.
His co-accused, Zaw Lin, was picked up on Koh Tao after he was identified by a friend.
The defendants issued a letter at the end of the trial hearing yesterday to say that they were comforted to have their mothers in court with them and to reiterate once again that they are innocent.
A fair trials observer, who was in court, repeatedly complained to the judges that journalists and observers have been banned from taking any notes on trial proceedings.
The accused deny charges of murder, rape and robbery.
The trial continues.
