Carbon monoxide poisoning was determined to be the cause of death for three Americans found dead at a Sandals resort in the Bahamas, a new report said Monday.

Autopsy and toxicology reports have been completed following the deaths of Tennessee couple Michael Phillips, 68, and Robbie Phillips, 65, and Florida resident Vincent Chiarella, 64, according to the Nassau Guardian.

The medical examiner said the cause of death was carbon monoxide poisoning. No further information was released.

The three Americans died under mysterious circumstances at the Sandals Emerald Bay resort on the island of Exuma on May 6 while staying in separate villas.

The victims were found unresponsive in their rooms after allegedly seeking medical help for feeling ill the prior night.

Chiarella’s wife, Donnis, was briefly hospitalized but recovered.

There’s been ongoing speculation about what might’ve caused the deaths, including an investigation into the food that was served. Several guests also complained that there was a strong odor of insecticides.

Possible leaks from the air conditioning and the water heater on the property are also being probed.

The families of the dead tourists demanded a second, independent autopsy in addition to the one by a Bahamian pathologist, the country’s Minister of Health and Wellness said in an interview with Eyewitness News last week.

“There’s still some investigations ongoing at the Sandals resort. We also have the pathologists in-country who have done their job and samples were sent to a very reliable lab in the United States,” Dr. Michael Darville said, according to Eyewitness News.

None of the deceased showed any trauma, but showed signs of convulsions, the Royal Bahamian Police said. Foul play isn’t suspected.