"I genuinely thought that was the day I was going to die. I phoned my mum, I phoned my sister. I told her I loved her and that I would try and make it home."
McAnna met Miller last year while both men were living in Leeds. He was the singer and guitarist in a Leeds band called These Fading Polaroids and Miller was an engineering student.
McAnna said he recently returned to Koh Tao, where he had previously spent 18 months living and working as a barman, and had planned but failed to meet Miller on the night he and Witheridge were murdered.
Police have yet to make any arrests for the murders and say they plan to force every man on the island, which has a population of 2000, to provide DNA for testing.
McAnna said he was accosted by two Thai men at Koh Tao's AC Bar. "They just said to me, 'It was you who killed them. You've got two people's deaths on your hands. We know it was you. You're going to hang yourself tonight and we are going to watch you hang. You will die tonight.' So I just ran. I just left and ran," he said.
McAnna took refuge in a supermarket into which the men chased him. They tried to convince him to leave but he refused.
McAnna posted information about the alleged threats on his Facebook page and issued a desperate plea for help. "Thai mafia are trying to kill me. Please help me," he wrote.
After spending much of yesterday in hiding, McAnna travelled to the island's port with British reporters. He left Koh Tao on a ferry around mid-afternoon.Telegraph Group Ltd