Semen found on the body of one of the two British tourists murdered on Koh Tao in Surat Thani province last Sunday will be examined in a Singapore laboratory, national police chief General Somyot Poompanmoung said yesterday.
Somyot said the DNA test would be able to identify the race, hair colour and skin colour of the person, which would help with the police investigation.
It is understood cigarette butts found at the crime scene will also be sent to Singapore for DNA analysis, although Somyot did not mention the butts in his remarks to reporters yesterday during a visit to the island.
Somyot had earlier said the authorities would ask the United States' Federal Bureau of Investigation to conduct the test, as the police's Institute of Forensic Medicine's DNA test was capable of only identifying the sex.
He said police had clues that pointed to the perpetrators of the crime being Asian men and he was "confident" they remained on the island in the Gulf of Thailand. Surveillance camera footage obtained one day after the brutal slayings showed an Asian-looking man running from the scene.
Somyot was speaking on Koh Tao, where police investigators simulated the crime using a few scenarios.
They were: the attackers followed the victims from a bar; the attackers randomly selected them after spotting them walking; with police following the route they suspect the attackers took before they killed the victims on the beach.
Somyot said police were trying to pinpoint how long the attackers were at the scene based on cigarettes that were discarded there. Police found, through DNA analysis, that one of the cigarette butts was smoked by two people, and semen from both men was found in the female victim's body.
Somyot said a theory had been established about another possible weapon used in the murder apart from a blood-stained garden hoe found near the crime scene. The theory centred on the weapon being returned from where it was taken from in a hurried manner.