Divers returned to the sea Friday in search of UK tycoon Mike Lynch's teenage daughter, the last person missing after their boat sank off Sicily killing the businessman and five others.
Italy's fire service said sea dives resumed in the early hours, continuing days of complex operations to recover bodies after the superyacht sank during a sudden storm before dawn on Monday.
"The long and delicate search operations for the last missing person continue," the service said on social media Friday.
Lynch, a celebrated technology entrepreneur and investor, had invited friends and family onto the sailing boat "Bayesian" to celebrate his recent acquittal in a massive US fraud case.
But as the 56-metre (185 feet) British-flagged yacht was anchored off Porticello, near Palermo, it was struck by a waterspout -- akin to a mini-tornado -- during a storm.
It sank within minutes.
Fifteen people were rescued, but one body, believed to be of the yacht's chef, was found a few hours later. Six people, including Lynch and his daughter, were reported missing.
After an intensive search involving specialist divers, boats from several emergency services and helicopters, Lynch's body was pulled up on Thursday, the day after another four bodies had been found.
The bodies of Lynch's lawyer Christopher Morvillo and his wife Neda, and Jonathan Bloomer, the chair of Morgan Stanley International, and his wife Judy, were also recovered.
A source close to the investigation had earlier indicated Lynch's daughter had yet to be found.
Many questions remain about why the yacht sank, and so quickly, when other boats nearby were unaffected.
On Thursday the head of the company which built the boat said the tragedy could have been avoided.
"Everything that was done reveals a very long summation of errors," said Giovanni Costantino, head of the Italian Sea Group, which includes the Perini Navi company that built "Bayesian" in 2008.
He told Italy's Corriere della Sera newspaper that bad weather was forecast and all the passengers should have been gathered at a pre-arranged assembly point, with all the doors and hatches closed.
"Instead it took on water with the guests still in the cabin. They ended up in a trap, those poor people ended up like mice in a trap," he said.
Lynch, 59, was acquitted on all charges in a San Francisco court in June after he was accused of an $11 billion fraud linked to the sale of his software firm Autonomy to Hewlett-Packard.
