A former politician faces life behind bars after being found guilty of drowning his wife during a scuba-diving trip in what prosecutors called a nearperfect murder in the British Virgin Islands a decade ago.

David Swain, 53, a diving shop owner and former council member in Jamestown, Rhode Island, was convicted of killing his wife Shelley Tyre, 46, so he could take her money and run off with his chiropractor lover.

Swain and his wife, a headmistress in the Boston area, travelled to Tortola in 1999 for a romantic Caribbean getaway. On the last day of their holiday, Ms Tyre was found dead in 80ft (24m) of water with her damaged mask hanging from her face and her mouthpiece missing. One of her flippers was found embedded toe-first in the sand.

The couple had been diving near the wreck of RMS Rhone, a Royal Mail Steam Packet Company vessel that sank in a hurricane in 1867. Island authorities ruled the death an accident and allowed Swain to take his wife’s body home, but her parents sued and won $3.5 million (£2.2 million) in damages.

They said that Swain, who had inherited $630,000 from his wife, would not have got anything under a prenuptial agreement if he had divorced her.

The 2006 civil verdict forced authorities to take a fresh look at the case and charge Swain with murder. The three-week trial in Tortola heard that Swain had wrestled his wife from behind under water, tore off her scuba mask and shut off her air supply.

Tom Neuman, an expert on diving deaths, said medical records indicated that Ms Tyre died about eight minutes into her dive. The torn mask and embedded fin “bespeaks some sort of violent activity”, he said. “This is a pretty benign place to dive. There is not a lot there that would cause a diver to panic.”

Bruce Allen Hyma, chief pathologist at Schneider Hospital in the US Virgin Islands, told the court: “This death is not a natural death. It is not a suicide. It is not an accident. It is a homicidal drowning.”

Prosecutors said that Swain’s intention was to run off with Mary Basler,who testified that she had become intimate with him about two months after his wife’s death.

In court, Swain said that he and his wife had gone their separate ways under water and that he had tried to resuscitate her when a friend found her body. “It was a horrible vision, seeing her with open mouth and open eyes,” he told the court. “I did not, could not, would not dream of taking the rock of my life out of this world.”

Swain faces life imprisonment when he is sentenced on November 4. His lawyer said that the verdict would be appealed.

Times Recommends

• Please help: maimed children of war want their lives back
• Cabal seizes diamond riches to buy power
• White House gatecrashers got to the president