The first result of tests on DNA taken from the son of an influential local leader on Koh Tao have shown no match with DNA found at the scene of the murder of two British tourists in September.
Warot Tuwichian (seated) shows the hand Chulalongkorn Memorial Hospital doctors took blood samples from at police headquarters on Thursday. (Photo by Pattarachai Prechapanich)
The Institute of Forensic Science at the Police General Hospital reported on Friday that tests of a DNA sample taken from Warot Tuwichian did not match the DNA in semen retrieved from the body of British tourist Hannah Witheridge, who was raped and murdered on a Koh Tao beach, and items found at the crime scene.
The 22-year-old university student was accused in the social media of possible involvement in the murders of Witheridge and her companion, fellow tourist David Miller, in the early morning of Sept 15 at Hat Sairee.
In response to the internet accusations, Mr Warot reported to police headquarters on Thursday for DNA tests to prove his innocence.
He was accompanied by father, Hat Sairee village chief Woraphan Tuwichian who owns AC Bar where the two murdered tourists had a quarrel with some men before being killed later that night.
Police are now waiting on results of tests on samples taken by Chulalongkorn Memorial Hospital, Siriraj Hospital and Ramathibodee Hospital.
The four hospitals took blood samples and mouth swabs from him on Thursday.
Police spokesman Pol Lt Gen Prawut Thawornsiri said all the test results will be made public no later than Saturday. Police were still waiting for the other three hospitals to submit their findings.
Police have arrested two Myanmar migrant workers on Koh Tao island and charged them with the murders of the two British tourists.
Zaw Lin and Win Za Htun were charged with murdering Miller, and killing and raping Witheridge. The suspects confessed during police interrogation but recanted their confessions on Oct 24, asserting they had been tortured by police to confess.
Parents of the two suspects filed a complaint with the Office of the Attorney-General and asked the National Human Rights Commission and the Lawyers Council of Thailand to step in, saying they were worried their sons would not get a fair trial.
The two suspects are detained at Koh Samui prison in Surat Thani province. Public prosecutors are awaiting more evidence from investigators before making an indictment decision.
National police chief Pol Gen Somyot Pumpanmuang said on Thursday that forensic police had not taken a sample for DNA testing from Mr Warot after the murders because he was not on the island when the crime occurred.
Posters on social media argued that the man shown in footage from a security camera in front of the bar on Sairee beach looked like him.