Tourists at a Sandals Bahamas resort where three Americans died have told of a “strong odour” of insecticide before the deaths.
Police identified the victims as a couple, Robbie Phillips, 65, and Michael Phillips, 68, of Tennessee, and Vincent Chiarella, 64, of Florida.
Mr Chiarella's wife was also airlifted and taken to the hospital in serious condition, said Police Commissioner Paul Rolle.
The two couples were staying in separate villas at the Sandals Emerald Bay resort, on the island of Great Exuma.
Samples were taken from the rooms as well as from the deceased to determine cause of death, according to Commissioner Rolle.
Several holidaymakers at the resort have told NBC News that they complained of a strong odour of insecticide before the deaths.
The police commissioner said authorities were "engaging" a laboratory in Philadelphia to run toxicology tests and that he expected pathology examinations to be performed on Monday.
The tests will determine if there were contaminants involved with guests having said that there had been a leaking air conditioner.
Police said in a statement that staff at the resort had found an unresponsive man in his room early on Friday morning.
Once authorities arrived at the resort, they also found an unresponsive man and woman in a separate villa. Both showed signs of "convulsion," police said, and all three were declared dead by a local doctor.
The couple, now identified as Robbie and Michael Phillips, had complained of illness on Thursday evening and visited a local medical facility, police said.
Donnis Chiarella woke up last Friday to find herself paralysed and her husband unresponsive, Austin Chiarella told ABC News.
"She woke up and my dad was laying there on the floor, and she couldn't move," he said.
"Her legs and arms was swollen and she couldn't move and she screamed to get someone to come in the door."
Austin also told how his mum had been ill the day before and visited a local doctor.
Health Minister Michael Darville told local media on Saturday investigators believe it was "an isolated situation" and that the resort was safe.
Another guest at the resort Chris Coucheron-Aamot suggested a faulty air conditioner could have been the cause of the deaths.
"Three of our neighbours in the building right next to us died and a fourth was airlifted in critical condition early yesterday," he posted on Facebook last Saturday.
"There was crime scene tape and security guards all around our unit. It sounds like it may have been a fault with the a/c in the unit, causing a toxic coolant leak."
The United States State Department told USA Today it was "closely monitoring local authorities' investigation into the cause of death."
A statement from Sandals resort was released confirming the deaths.
It read: “We are actively working to support both the investigation and the guests’ families in every way possible during this difficult time.
"Out of respect for the privacy of our guests, we cannot disclose further information at this time."
