PHUKET: Some of Thailand's top toxicologists were working today to determine what caused the mysterious deaths of Canadian sisters Audrey and Noemi Belanger on Phi Phi island.

For the first time, Dr Duangporn Paothong of Phi Phi Hospital talked publicly about what she found when she was called to the room at the Palms Residence Phi Phi immediately after a maid discovered the bodies on Friday.

The photographs in the album above show the room, from the resort next door, from where a young English law student said he also saw the bodies.

Dr Duangporn told Phuketwan today that she had ''never seen a case like it.''

''Both bodies had the same characteristics,'' she said. ''There was a lot of vomit in a wastepaper basket.

''There was blood under their skin, under their tongues and under their eyes. Their fingernails had turned green or purple.

''As for the cause of death, it's impossible to know at this stage,'' she said. ''There just isn't enough information.''

Dr Duangporn said she had been on Phi Phi, a holiday island popular with 20-somethings, for three years but was not familiar with the case at Laleena guesthouse in 2009 when two young female tourists in adjoining rooms took sick and died.

No cause of death has ever been established for American Jill St Onge, 27, and Norwegian Julie Bergheim, 22. Two other people travelling with the women also fell seriously ill.

But the survivors were not able to clarify what might have caused the deaths. Miss St Onge's fiance, Ryan Kells, suspected chemicals or a gas. He said he smelled a chemical smell when he and Miss St Onge arrived at Laleena.

Thai toxicologists were returning to Phi Phi today to more closely examine the room at the Palms Residence Phi Phi, although other sources said it had been thoroughly cleaned.

It is believed the same team who closely examined the Downtown Inn in Chiang Mai after the deaths of Sarah Carter and several other tourists last year in mysterious, undetermined circumstances are now involved in the latest investigation.

The bodies in Chiang Mai and on Phi Phi in 2009 were not reported to have suffered the same kind of bleeding.

Phuketwan was at the scene on Phi Phi yesterday and saw police remove a number of samples in a clear plastic bag, pictured in the photo album above. Medication, pills, a set of headphones and other unidentified material appeared to be in the bag.

Dr Duangporn said the bodies of the two women were still in Krabi Hospital this morning, with a team of toxicologists from Bangkok performing further examinations and deciding what should happen next.

Reports from Canada said that members of the Belanger family were on their way to Thailand. Canadian Embassy officials have been closely involved with the investigation.

In the 2009 deaths, Miss St Onge was cremated in Thailand before her remains were returned to the US. Mr Kells said officials on Phi Phi had virtually pushed him off the island very soon after his fiancee died, with her body in a bag in the bottom of the speedboat.

Miss Bergheim's body was returned to Norway where a second autopsy was performed. Even some of her home country's best pathologists could not determine what killed her.

Theories of all kinds have sprung up since the bodies of the Canadian women were found dead on the bed in a ground-floor room at the Palms Residence Phi Phi.

Dr Duangporn and other professionals were not speculating today about causes.

Phi Phi was packed with young tourists yesterday, when a Phuketwan team crossed on the 100-minute ferry ride from Phuket.

A team of regular police in civilian clothes and Tourist Police in neat white uniforms were busy at the resort. People were coming and going, as if nothing had happened.

A sign on the front of the reception desk said ''Welcome'' while another sign on top said ''FULL.''