Divers searching the wreck of a superyacht owned by the family of a British tech mogul that sank Monday off the coast of Sicily in southern Italy were working Wednesday to recover the remains of most of the six people left missing after the accident, Sicily’s civil protection agency confirmed to CBS News. Two bodies had been brought to shore in Porticello, near Palermo, and two more were in the process of being brought ashore.

Five bodies have been found, and one person was still missing, reported the AP, as searches concluded for the day. 

Rescue efforts have been challenging because the Bayesian is now lying on the seabed at a 90-degree angle, at a depth of 164 feet.  Divers can only spend 10 minutes at the dive site before having to resurface to avoid decompression sickness, or “the bends.”

Britain’s Telegraph newspaper reported that the bodies of Mike Lynch, the technology entrepreneur, and his 18-year-old daughter were among the remains recovered Wednesday, but the civil protection chief would not confirm that report to CBS News. 

Six people, including Lynch and his daughter, were left missing after the vessel sank in a violent storm early Monday morning. One man, the Bayesian superyacht’s chef, was found dead soon after the boat capsized.

Fifteen passengers and crew managed to escape the accident, including Lynch’s wife, who owned the vessel.

Along with Lynch and his daughter Hannah, the technology mogul’s American lawyer Chris Morvillo, a former assistant district attorney in New York, his wife Neda, and British banker Jonathan Bloomer, chairman of Morgan Stanley International, were also missing.

Lynch was acquitted in June of fraud charges in the U.S. that could have landed him in prison for decades. Lynch’s co-defendant in that fraud case, who was also acquitted, died Saturday after being hit by a car while out jogging in England.

Questions have intensified on how the state-of-the-art vessel could have sunk in mere minutes, while boats nearby were largely unaffected.  Vessels of this caliber have numerous safety measures, including watertight sub-compartments designed to keep them from sinking quickly even if taking on water.

Italian prosecutors are questioning the crew and passengers in an effort to reconstruct events, including the ship’s captain, 51-year-old New Zealander James Catfield. 

One possible culprit is the ship’s keel, a fin-like structure designed to prevent the boat from being blown sideways by the wind, thus giving the boat greater stability.  The Bayesian had a retractable or lifting keel, which could be retracted to 4 meters (useful to enter a shallow harbor) or extended to 10 meters. If the keel had been up, it is possible that fierce winds could have caused the ship to capsize.

When asked whether divers had discovered that the Bayesian’s keel was indeed up, a spokesman for the Italian Coast Guard told CBS News that it was up to the prosecutors to answer that question.