BANGKOK -- Two Canadian sisters were found dead in their hotel room on a popular resort island in southern Thailand, but did not appear to have been murdered and their belongings had not been taken, police said Sunday.
Police were attempting to determine the cause of death of Noemi Belanger, 25, and her 20-year-old sister Audrey, whose bodies were found by a maid Friday at the Phi Phi Palm Residence Hotel on Phi Phi Island, said police Lt. Col. Jongrak Pimthong.
"Police determined they were dead for about 24 hours prior to that and only found a lot of vomit in the room," he said. The vomit, along with traces of blood on the women's faces, could be signs of a toxic reaction, police said.
A team of investigators combed through the hotel room on Sunday, Jongrak said by telephone.
"There were neither signs of fighting, nor robbery, but we found many kinds of over-the-counter-drugs, including ibuprofen, which can cause serious effects on the stomach," he said.
Jongrak said the most important evidence would be an analysis of the contents of the victims' stomachs. The bodies will be sent to the Central Forensic Institute in Bangkok for further examination, he said.
He said officials from the Canadian Embassy in Bangkok also visited the hotel on Sunday.
Canadian Foreign Affairs spokesman John Babcock said consular officials in Bangkok were providing assistance to the family and were in contact with local authorities.
Tourists' deaths are not uncommon in Thailand, which was visited by about 19 million foreigners last year. The causes range from road accidents to foul play and drug overdoses.
The hotel, where the women checked in on Tuesday, is in an upscale area of the island, which is known for its partying and as the location where the movie "The Beach" starring Leonardo DiCaprio was filmed. Thai media earlier quoted another police officer, Lt. Siwa Saneha, as saying the two went out to socialize on the night of their arrival. He said a hotel maid sought to clean their room on Wednesday and Thursday, but did not enter because she believed they were inside.
On Friday, "the maid wanted to check if they wanted to stay at the hotel for another night but didn't hear any response, so the hotel used a spare key to access the room," Jongrak said.
He recalled a similar incident on Phi Phi Island in May 2009 when two women from the United States and Norway died after suddenly falling ill at a guesthouse. The victims in that case also suffered severe vomiting and stomach pains. Doctors determined the immediate cause of death as dehydration and shock, but it was not known what caused their sudden illness. Two other people with the same symptoms survived.
Another spate of mysterious tourist deaths last year in the northern city of Chiang Mai involved several visitors from different countries who stayed at the same hotel. The cause of death was not established, though some evidence suggested the chemical spray chlorpyrifos, used to kill bedbugs, may have been responsible.