Shark Tank star Barbara Corcoran's brother John, 60, was found dead in his Dominican Republic hotel room while on vacation with a friend in April, TMZ reports. While an autopsy has not been performed, Barbara was told that her brother suddenly died of a heart attack, which if true, coincides with an eerie string of American tourist deaths that have occurred in similar circumstances on the island.

Within the last year, six Americans have died at the Hard Rock Hotel & Casino Punta Cana, and Bahia Principe Hotels & Resorts, showing nearly identical causes of death. Miranda Schaup-Werner was celebrating her nine-year wedding anniversary at the Luxury Bahia Principe Bouganville hotel last month when she suddenly died after having a drink from the mini-bar.

Schaup-Werner's death came just five days before an American couple from Maryland were found dead at the same resort. Cynthia Ann Day and Edward Nathaniel Holmes were discovered in their room after missing their checkout time. Republic National Police revealed their autopsies showed that they had experienced respiratory failure and pulmonary edema, a fluid buildup in the lungs. Schaup-Werner's family claims she died of the same lung condition.

It's unclear what hotel Corcoran was staying in the Dominican Republic when he was found dead. It's also unknown if he had a drink from the mini-bar.

Kaylynn Knull and Tom Schwander filed a lawsuit against the Grand Bahia Principe Hotel La Romana resort earlier this year after becoming sick during their stay in 2018. The Colorado couple suspect that the release of insecticides into the central air conditioning system led to their sickness.