Police officials interrogated Woraphan Toovichien, 49, a village headman and owner of AC Bar which is located near the murder scene, and his brother, Montriwat Toovichien, owner of In Touch resort and caretaker of AC Bar.
Both cooperated with the police and they denied they had any connection to the murders.
DNA samples of the two brothers were collecting for testing and were later proved to not match with DNA collected from the scene and the victim’s body.
Pol Lt-Gen Panya Mamen then stated that the suspects were not arrested but were just in police custody and that more test would be conducted. They are still hunting for another suspect who is the son of the AC Bar’s owner and was reported to flee into Bangkok.
Montriwat Toovichien is one of the two men that appeared on British musician, Sean McAnna Facebook, claiming that they threatened to hang him if he didn’t confess to the murders of the two Brits.
Sean told The Telegraph News he had to run for his life from the island after he was threatened by local mafias, and posted the picture of two men which he took by his mobile phone.
Sean also said he was among a group of people playing guitar on the beach near the scene.
Mr. Montriwat discredited the Briton’s claim saying in fact on the night of the murder an employee of a spa has told him she helped to wash and clean blood from the face and body of Mr Sean who is a friend of the murdered David Miller.
He said he asked Mr Sean about the blood on his face and body and insisted on asking where he was that night.
Police freed both Montriwat and his brother Woraphan after blood and urine test came up negative to DNA collected from the scene.
Police also confirmed no drugs were found in either of the samples provided.
Police have confirmed that Montriwat is the man appeared in the CCTV video footage near the scene and they still did not rule out a possible connection.
Police questioned why Wiraphan’s son Warot, 22 quickly disappeared from the island shortly after the murders however he stated that his son was studying at a university in Bangkok and he was returning to study, not running as the police said.
They are also consulting lawyers to consider legal action for such allegations by the police that they were involved.
However the Khaosod News has reported that Mr. Warot is currently the primary suspect as DNA test results have cleared all others previously detained by police.
Police reportedly collected DNA and footprint samples from more than 160 residents on the island, many of them Burmese migrant workers, in an effort to find a match with the DNA traces found on Ms. Witheridge’s body and a cigarette near the crime scene.
Meanwhile, a police source said it was impossible that people on the island couldn’t have any knowledge of what might have happened on the night of the murder. Police believe that people don’t want to come forward as they do not want to have problems with an influential group.
Udom Tantiprasonchai, an executive with Orient Thai Airways, said he will add Bt500,000 to the bounty placed for arrest of the killers, Senee Puwasettathaworn, president of Koh Samui Tourism Association, said.
This sum will bring the total bounty up to Bt713,000.
Though the murders took place more than a week ago, and police have yet to charge anyone, tourism has not been affected too badly as it is still the low season. Local tourism operators, meanwhile, said they would not put any pressure on police, leaving them to focus on the job at hand.