British technology tycoon Mike Lynch is among six tourists missing after a luxury yacht sank in a tornado off the coast of Sicily, sources said.

A body, believed to be that of the vessel’s chef, has been found and 15 people including Mr Lynch’s wife were rescued, according to local media.

Four of the missing passengers are British and two are American, Italian news website la Reppublica stated.

The British-flagged superyacht, named Bayesian, capsized at about 5am local time off the coast of Palermo when the area was hit by a tornado.

The body was found near the wreck at a depth of 50m (164ft), fire and rescue services said.

Mr Lynch, who founded software giant Autonomy in 1996, was made an OBE for services to enterprise in 2006.

Earlier this year he was cleared of conducting a massive fraud relating to an 11 billion dollar (£8.64 billion) sale to US company Hewlett Packard.

A spokesperson for Mr Lynch said there was no comment.

The yacht sank as a fierce storm battered the area overnight.

The daily Il Giornale di Sicilia newspaper reported that the vessel had mostly British passengers on board, but also people from New Zealand, Sri Lanka, Ireland and British-French citizens.

One of the survivors, a British tourist named Charlotte, told la Reppublica she held her one-year-old daughter, Sofia, to stop her from drowning.

She said: “I held her afloat with all my strength, my arms stretched upwards to keep her from drowning.

“It was all dark. In the water I couldn’t keep my eyes open. I screamed for help but all I could hear around me was the screams of others.”

Charlotte and Sofia are being treated in hospital, as is Charlotte’s husband, James.

Karsten Borner, captain of a nearby boat, told journalists those missing included the Bayesian’s owner and a child, news agency Reuters reported.

He said his crew took on board some survivors who were on a life raft, including three who were seriously injured.

Fisherman Francesco Cefalu said he sailed from the shore to the scene after seeing a flare at about 4.30am, but by the time he arrived Bayesian had already sunk, with only items such as cushions and wood floating in the water.

He added: “I think they are inside, all the missing people.”

A spokesman for the Foreign, Commonwealth and Development Office (FCDO) said: “We are in contact with the local authorities following an incident in Sicily, and stand ready to provide consular support to British nationals affected.”

Bayesian completed a number of sailings in recent days, calling at various ports in Sicily, according to ship-tracking website VesselFinder.

The superyacht can accommodate up to 12 guests in six suites, and is listed for rent for up to 195,000 euros (£166,000 ) a week.

She was built in 2008 by Italian company Perini Navi.

Her registered owner is listed as Revtom Ltd.

There is little publicly-available online information about the company, which appears to be based on the Isle of Man.