Barbara Corcoran shares brother had an existing heart condition prior to his death in Dominican Republic

Barbara Corcoran is speaking out about the recent death of her brother, John.

Corcoran's rep told ET on Wednesday that John died in late April in the Dominican Republic of what is believed to be natural causes. Still, the news was alarming given the recent reports of multiple American tourists' deaths while they were vacationing at resorts in Punta Cana.

But Corcoran took to Instagram on Thursday to share that her brother actually had an existing heart condition, and she also gave her condolences to the families of the tourists who have recently died in the Dominican Republic.

"It's made it to the news by now that my dear brother John passed away in the Dominican Republic back in April," the 70-year-old Shark Tank star wrote. "He loved the DR and vacationed there frequently."

"My brother had an existing heart condition and we believe he died of natural causes, but you're still never ready for the death of a loved one," she continued. "I'm overwhelmed with sadness for the lost lives in the DR and my thoughts are with the families who have lost their loved ones. Thank you for all of your thoughts and good wishes. I appreciate your love and kindness."

Corcoran previously told TMZ that 60-year-old John was found dead in his hotel room by his friend he was vacationing with, and that she was told he died of a heart attack. John -- who was one of Corcoran's nine siblings -- was retired after owning and operating a successful roofing company in New Jersey. According to the outlet, he was waiting on the arrival of his girlfriend in the Dominican Republic before he died.