Hannah Witheridge, 23, and David Miller, 24, were found semi-naked and brutally murdered on the island’s main beach Sai Ree on Monday.
The BBC reported that two British men were now possible suspects, and had spent time with the victims in the days before they died.
The men, believed to be brothers, are not in custody but are being escorted by police in Bangkok, the BBC said.
On Tuesday police released still images from CCTV footage in the area, one of which showed a man of Asian appearance who they believed was the prime suspect.
“We are focusing on migrant workers because of the surrounding witnesses and evidence, including the video footage,” senior police official Maj Gen Kiattipong Khawsamang said.
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