The Italian Coast Guard said Thursday the body of British tech magnate Mike Lynch is among those recovered off the coast of Sicily from the wreckage of a superyacht whose builders had called it unsinkable.

The bodies of Lynch and four others were recovered by rescue crews. One woman remains missing.

The Bayesian, a 56-metre British-flagged yacht, went down in a storm early Monday as it was moored about a kilometre from shore. Civil protection officials said they believe the ship was struck by a tornado over the water, known as a waterspout, and sank quickly.

Fifteen of the 22 people aboard survived, including a mother who reported holding her one-year-old baby over the waves to save her.

Lynch had been celebrating his recent acquittal on fraud charges with his family and the people who had defended him at trial in the United States.

WATCH l Why the search effort has been a struggle for divers: 

Sicily superyacht rescue: What divers are up against | About That

Rescue efforts are underway in Sicily, after a luxury superyacht carrying 22 people was hit by a violent storm, causing it to suddenly capsize. Lauren Bird explains the challenges that divers face in finding the six missing passengers, and breaks down why time isn't on their side.

Divers have struggled to find the bodies.

"It's very difficult to move inside the wreckage. Moving just one metre can take up to 24 hours," said Luca Cari, spokesperson for the fire rescue service.

Hannah Lynch, the businessman's 18-year-old daughter, is among the boat occupants rescue teams were searching for this week, along with Judy and Jonathan Bloomer and Chris and Neda Morvillo.

Lynch's wife was among those who managed to get to safety, while the body of the onboard chef, Recaldo Thomas, was found near the wreck hours after the disaster.

Thomas was a native of Antigua but was raised in Calgary, according to Antiguan reports.