Authorities in the Dominican Republic along with the FBI are investigating the deaths of six American tourists at various resorts throughout the country over the last year.
In April, Robert Wallace of California got sick almost immediately after drinking a scotch from the minibar at the Hard Rock Hotel and Casino.
He died three days later.
David Harrison of Maryland died at the same resort after unexpectedly falling ill.
He and his wife were with their 12-year-old son to celebrate their wedding anniversary.
An autopsy shows he died of a heart attack.
SOUNDBITE: DAWN MCCOY, WIFE OF DAVID HARRISON, SAYING: "I didn't plan on coming back a widow... words can't describe my life got turned upside down when he passed." Miranda Schaup-Werner and Yvette Monique Sport died at the Bahia Principe Resort.
Their death certificates say they died of heart attacks.
But Sport's sister isn't convinced.
SOUNDBITE: FELECIA NIEVES, YVETTE MONIQUE SPORT'S SISTER, SAYING: "There is something dirty at the bottom of all this.
We were promised within 3 months that we would receive a toxicology report to this day, almost a year now we've got nothing." The most recent deaths happened in late May.
Edward Holmes and Cynthia Day were celebrating their engagement before both died in their room at the Bahia Principe La Romana.
Tourism is one of the Dominican Republic's main economic drivers -- the country's tourism minister recently said the island nation remains safe for travelers.