Images received from Britain's Foreign and Commonwealth Office show Hannah Witheridge and David Miller.

Story highlights

Burmese migrants who had previously confessed to double murder retract confessions

Lawyer acting for the two says his clients claim they were physically abused by police

Police had held a press conference the previous day to deny torturing suspect

Amnesty International condemns act, calls for independent investigation

CNN  — 

Two Burmese migrants accused of the brutal murder of two British tourists on a popular tourist island in Thailand last month have retracted their confessions, a lawyer representing them says.

Zaw Lin and Win Zaw Htun, who have been in custody since October 1, had admitted to killing David Miller and raping and murdering Hannah Witheridge on Koh Tao, according to Thai police.

However the men now say they did so under duress after being physically abused by police, Surapong Kongchantuk, the head of the Lawyers Council of Thailand, which is acting for the two suspects, told CNN Wednesday.

Surapong said the men deny the murder and rape charges, and that an official complaint to the justice department of Samui, which has jurisdiction over the island, has been filed. They appealed for fair treatment for the two accused, he added.

Thai police could not be immediately reached for a response.

The Ocean View Bungalows hotel where the two British backpackers stayed.

The two Britons were found dead on a beach on the island, a popular tourist destination, on September 15. Both were partially undressed with severe injuries to their heads. A hoe with blood on it was found close by, police said.

Police Commissioner Gen. Somyot Poompanmuang previously told CNN that DNA in semen taken from Witheridge matched samples taken from the two men. “The DNA matching result is out already and they matched with DNA found on the female victim,” he said.

Torture claims denied

Reports that the police extracted confessions through torture first surfaced earlier this month, when Burmese media reported that its two nationals had complained to a visiting lawyer attached to the Myanmar embassy.

The revelation prompted national police chief Somyot Poompanmuang to hold a press conference in Bangkok to deny allegations his officers had tortured the suspects.

Nevertheless, Amnesty International has called for a full, independent investigation into reports of misconduct by police officers. Allegations of torture should be investigated independently, and not by the Thai police, Richard Bennett, Amnesty’s Asia-Pacific Program director, told CNN earlier this month.

He also said there were questions of due process that had arisen, specifically the absence of legal counsel prior to the confession, and difficulties with interpretation.

“There is a fairly long-standing record of ill-treatment,” in Thailand, he said. “Impunity is also a problem. If the investigation shows ill-treatment, those responsible should pay.”

The fact that the suspects are migrant workers, many of whom work in Thailand illegally, makes them more vulnerable, he added.

Journalist Kiki D in Bangkok contributed to this report.