NEW YORK • Dominican government officials have released more detailed autopsy results for three American tourists who died at adjacent beach resorts owned by the same hotel company during the last week of May.
All three victims experienced eerily similar symptoms and internal trauma before their deaths, according to a news release from the Dominican authorities.
Pathologists said autopsies showed the three had internal haemorrhaging, pulmonary edema and enlarged hearts.
Toxicology reports are pending.
A US State Department official said the authorities have not yet established a connection between the May 30 deaths of Ms Cynthia Ann Day, 49, and Mr Nathaniel Edward Holmes, 63, both from Prince George's County, Maryland, and the May 25 death of Ms Miranda Schaup-Werner, 41, of Pennsylvania.
The Federal Bureau of Investigation is providing Dominican law enforcement with "technical assistance with the toxicology reports", the State Department official said.
Ms Schaup-Werner had just checked into the Luxury Bahia Principe Bouganville in the town of San Pedro de Macoris, and was taking pictures from her room balcony when she started to feel ill.
Less than two hours later, she was dead, the local authorities said.
The bodies of Ms Day and Mr Holmes were found inside their room at the Grand Bahia Principe La Romana after relatives grew concerned because the couple had not checked out of the resort.
The hotels are located next to each other on the island's southern coast.
The Dominican authorities initially did not run toxicology tests for Ms Schaup-Werner because there were no signs of violence, said Mr Ramon Brito, a spokesman for the National Police's special tourism unit.
The Maryland couple had posted photos of themselves on Facebook enjoying time on the beach. On May 26, Mr Holmes posted: "Can somebody please loan me US$250,000 (S$341,000) because I don't want to come home!"
More than two million North American tourists flock to the Dominican Republic every year.
But after an attack on a Delaware woman inside her resort near the tourist area of Punta Cana in mid-April, the State Department alerted travellers to exercise "increased caution in the Dominican Republic due to crime".
After the couple was found, investigators ordered a set of tests to determine whether anything the three Americans consumed may have led to their deaths, Mr Brito said.