An American couple disappeared in the Caribbean after three escaped prisoners allegedly used their yacht to island-hop before being recaptured by authorities, investigators say.

Ralph Hendry and his wife Kathy Brandel disappeared from their yacht, Simplicity, which was docked in the waters of the southern Caribbean nation of Grenada, Hendry’s sister, Suellen Desmarais, told ABC News.

Police have not confirmed the identity and nationality of the couple, but are investigating the incident.

PHOTO: Ralph Hendry and Kathy Brandel are seen in this undated photo.

Ralph Hendry and Kathy Brandel are seen in this undated photo.

Courtesy of Suellen Desmarais

Hendry and Brandel were last seen alive by their boating neighbor at the dock on Sunday afternoon, according to Desmarais. The neighbor said he saw the couple entering a restaurant, Desmarais said.

“That man went to bed that night and looked up and Simplicity was there when he went to bed,” but when the neighbor “got up at 6:30 a.m. Monday morning, Simplicity was gone.” , he told ABC News.

Desmarais said the couple had been in Grenada for about two weeks and their yacht left the island a week earlier than planned.

The Royal Grenada Police Force said the yacht allegedly became the target of three suspected criminals, Ron Mitchell, Trevon Robertson and Abita Stanislaus, all from St. Andrew, Grenada, who escaped from a police station after being arrested on Sunday.

They were jointly charged with robbery with violence before escaping, police said. Mitchell was also charged with rape, attempted rape and indecent assault, according to investigators.

The three fugitives allegedly managed to reach a neighboring Caribbean country using the yacht, but were captured by police in St. Vincent and the Grenadines on Wednesday, according to authorities.

PHOTO: Ralph Hendry and Kathy Brandel's yacht, Simplicity.

Ralph Hendry and Kathy Brandel’s yacht, Simplicity.

Courtesy of Suellen Desmarais

Grenada police said they are “currently working on leads that suggest the two occupants of the yacht may have died in the process.”

The Salty Dawg Sailing Association, a sailing association to which the couple belonged, said in a statement that a good Samaritan boarded the yacht when it was anchored and abandoned off a St. Vincent beach and contacted them and the Guard. Costera when he found no one inside.

The good Samaritan allegedly “found evidence of apparent violence,” according to the association.

“I have spoken to the families and offered our deepest condolences and help in any way possible. In all my years of sailing in the Caribbean, I have never heard of anything like this,” said Bob Osborn, president of SDSA, in a statement. Friday afternoon.

The investigation is ongoing.

The couple, who lived on the boat, had been sailing the same route for several years, Desmarais said. That route began in Virginia, followed by a stop in Massachusetts, then to Florida to see Desmarais and his family, before heading south to island-hop in the Caribbean.

Hendry and Brandel’s two sons and Desmarais’ son traveled to St. Vincent and the Grenadines on Friday to join the search.

“Their love for life and the people of the island, they are good, basic people,” Desmarais said. “Until they find a body, they will stay alive.”

By Sam