British tech giant Mike Lynch, his lawyer and four other people are among those missing after their luxury superyacht sank during a freak storm off Sicily, Italy's civil protection and authorities say. Lynch's wife and 14 other people – including a one-year-old girl – survived but the entrepreneur was among the six people who remained unaccounted for after their chartered sailboat sank when a waterspout struck the area overnight, Salvo Cocina of Sicily's civil protection agency said. The sailboat overturned sometime before 5am on Monday (1pm AEST) off the port of Porticello, near Palermo in southern Italy, where it was anchored.

READ MORE: China accuses the Philippines of deliberately crashing ship into Chinese vessel A photo on Sunday night shows the UK vessel Bayesan, left, and the Duch sailboat Sir Robert Baden Powell at anchor off the Sicilian village of Porticello near Palermo. (AP) Lynch founded business software firm Autonomy and ran it as CEO until computer giant Hewlett Packard bought it in 2011. One body has been recovered, and police divers were trying to reach the hull of the ship, which was resting at a depth of 50 metres.

The yacht had a crew of 10 people and 12 passengers, including British, American and Canadian nationalities, the Italian coast guard said. A sudden fierce storm had battered the area overnight, and struck the place precisely where the 56-metre (184-foot) British-flagged Bayesian had been moored. "They were in the wrong place at the wrong ti.