(Reuters) - A prominent New York lawyer who is among six missing passengers of a sunken yacht off Italy's coast was traveling with his longtime client, British tech entrepreneur Mike Lynch, just weeks after helping him avoid conviction in a 12-year legal saga. Divers were still searching on Tuesday for the defense lawyer and former federal prosecutor Christopher Morvillo, a partner at law firm Clifford Chance, and his wife Neda, along with Lynch and three other missing passengers. There are 15 known survivors.

The British-flagged Bayesian, a luxury 56-metre-long (184-ft) superyacht, was carrying 22 people and anchored off the Sicilian port of Porticello when it was hit by a fierce, pre-dawn storm on Monday and sank. Ayla Ronald, a London-based senior associate at Clifford Chance, and her partner were among the survivors, the London-founded global law firm said in a statement on Tuesday. Ronald has also represented Lynch, according to her profile on the firm's website.

"We are in shock and deeply saddened by this tragic incident," a Clifford Chance spokesperson said. Morvillo, 59, was a lead lawyer for Lynch and won his acquittal in June after a three-month-long San Francisco fraud trial stemming from Hewlett-Packard's ill-fated acquisition of Lynch's software company Autonomy, and has represented the UK entrepreneur since 2012. He is the son of Robert Morvillo, considered one of New York's savviest criminal-defense attorneys before his death in 2011.

The younger Morvillo is a.