ROME (AP) -- Prosecutors in Italy are investigating the captain of a superyacht that sank during a storm off Sicily last week, killing seven people, on possible charges including manslaughter, his lawyer said Monday.

James Cutfield, the 51-year-old New Zealand national who was captain of the Bayesian, was among 15 survivors of the Aug. 19 sinking that killed British tech magnate Mike Lynch, his daughter Hannah and five others.

Cutfield is being investigated for possible manslaughter and culpable shipwreck, said lawyer Aldo Mordiglia, one of two attorneys appointed for the captain's defense.

Mordiglia said Cutfield, who already has been questioned, would be questioned again by prosecutors on Tuesday. He declined to discuss the strategy for the defense.

Under Italian laws, being under investigation doesn't imply any guilt, and doesn't necessarily lead to criminal charges.

On Saturday, chief prosecutor Ambrogio Cartosio confirmed that an investigation had been launched. He said his team would consider each possible element of responsibility including those of the captain, the crew, individuals in charge of supervision and the yacht's manufacturer.

The 56-meter (184-foot) British-flagged luxury yacht went down near the Mediterranean island in southern Italy. Investigators are focusing on how a sailing vessel deemed "unsinkable" by its manufacturer, Italian shipyard Perini Navi, sank while a nearby sailboat remained largely unscathed.

Prosecutors said the event was "extremely rapid" and could have been a "downburst" -- a localized, powerful wind that descends from a thunderstorm and spreads out rapidly upon hitting the ground.

The crew was saved, except for the chef, while six passengers were trapped in the hull.