One possible line of inquiry reportedly being looked into is whether bootleg alcohol is to blame for the spate of deaths and illnesses in resorts at the popular Caribbean holiday destination.
Some of those who died are reported to have consumed alcohol from the minibar in their hotel room before their deaths – however it is not known whether there is any connection at this stage.
Officials in the Dominican Republic have said the deaths over the last year are isolated incidents and that the country is still a safe destination.
Leyla Cox, 53, became the eighth American to die on the island after she was found dead in her hotel room at Excellence Resort in Punta Cana on 10 June, just a day after her birthday, her family said.
The MRI technician’s son Will Cox said his family did not know the cause of his mother’s death and that her body had not yet been returned to her home in Staten Island, New York.
Bride-to-be Yvette Monique Sport, 51, of Pennsylvania, was the first tourist to die after drinking from a minibar at Bahia Principe hotel in Punta Cana in June 2018.
A month later, David Harrison, 45, of Maryland, died from an apparent heart attack at the Hard Rock Hotel and Casino in Punta Cana.
In April this year, Robert Bell Wallace, 67, from California, reportedly fell ill and died four days later after drinking a whisky at the same Hard Rock Hotel.
That same month, John Corcoran, the 60-year-old brother of TV star Barbara Corcoran, who appears on America’s version of Dragons’ Den, died from an apparent heart attack while holidaying on the island.
In May, Miranda Schaup-Werner, 41, from Pennsylvania, checked into the Luxury Bahia Principe Bouganville with her husband.
She is said to have fallen ill after having a drink from the minibar in their room and died a short while later.
Five days later, Edward Holmes, 63, and Cynthia Day, 49, were found dead in their room in neighbouring Grand Bahia Principe resort.
Excess fluid in the lungs was listed among the causes of their deaths in preliminary reports, according to NBC news.
The US embassy in the Dominican Republic said the FBI had been called in to carry out toxicology reports, but that the results could take up to 30 days.
It said in a statement last week: “These incidents are tragic and we offer our deepest condolences to those personally impacted.
“Dominican authorities have asked for FBI assistance for further toxicology analysis on the recent Bahia Principe, La Romana, cases and our FBI colleagues tell us that those results may take up to 30 days.
“We ask everyone to be patient while these investigations run their course.”
Francisco Garcia, the country’s tourism minister, called the deaths “isolated incidents” earlier this month and said that the Dominican Republic was a “safe destination”.