Initial examinations of four of the people killed when British tech tycoon Mike Lynch's family yacht sank off Sicily last month indicated they had died of suffocation as oxygen ran out on the stricken vessel,

Italian authorities have confirmed increased security around the wreck of the luxury yacht Bayesian, which sank in August, claiming seven lives, including that of British tech entrepreneur Mike Lynch.

Lynch, who had connections with various intelligence services through his companies—including the cybersecurity firm Darktrace, which was recently sold to a private equity firm—had previously advised British prime ministers on technology and cybersecurity matters.