The sisters, aged 26 and 20, were found dead on Friday afternoon by hotel staff on the Andaman sea island, 800 kilometres south of Bangkok.
“Their bodies were found a little after midday [on Friday]. They were sisters,” Pol Lieutenant Pongpan Waiyawat told AFP. “We have to wait for the post-mortem to determine the cause of death, but based on initial investigations there’s no sign of violence in their room.”
Koh Phi Phi has a reputation for boisterous nightlife and binge drinking – tourists are sometimes encouraged to drink alcoholic concoctions out of small plastic buckets.
The latest tragedy echoes the mysterious death of two women tourists in a guesthouse on the island, which is about an hour’s boat-ride from Phuket, three years ago.
The Phuketwan website said: “American Jill St Onge, 27, was in one room with her boyfriend Ryan Kells, while Norwegian Julie Michelle Bergheim, 22, and her friend ‘Karina’ signed in for the room next door. Within hours, St Onge and Bergheim were dead, and Kells and ‘Karina’ narrowly avoided the same fate. The Laleena guesthouse has since changed its name but the mystery lives on. Despite pathologists and chemists in Norway and the US trying to solve the mystery, no cause of deaths has been determined. The fact that the 2009 deaths remain unsolved and the victims were also young women is likely to lead to intense media coverage”.