Meanwhile a source said their detention came after witnesses told police that they were seen drinking alcohol around the time when the crime occurred.
Police raided a worker’s bungalow near the crime scene earlier today, and detained the three Myanmar workers.
Four mobile phones, one of which was a broken iPhone, were confiscated. Police will examine them to determine if any of the phones belonged to the victims.
The suspects’ clothes were also seized, while police have been questioning them to look for any signs pointing that they had a hand in the murders.
Meanwhile British Embassy Consul Michael Hancock arrived at the crime scene along with Thai Tourist Police to follow up on the case.
The Phangan Police Station superintendent said the island would not be closed to visitors, ensuring that he has mobilised sufficient police to oversee safety on the area and to be on the lookout for suspicious persons.
The bodies of the two British nationals' bodies, who the Thai police identified as Hannah Victoria Witheridge, a 23-year-old woman from Great Yarmouth, Norfolk, and David William Miller, a 24-year-old man from Jersey, Channel Islands, were discovered half naked on Koh Tao yesterday morning.