Italian authorities are expanding their investigation into the deaths of seven people on the yacht, the Bayesian, to include two crew members as well as the captain, according to Italian news agencies.
British tech entrepreneur Mike Lynch and six others lost their lives when the 56m (184ft) yacht, flying a British flag, sank off the coast of northern Sicily on 19 August.
On Monday, the yacht's 51-year-old captain, New Zealand national James Cutfield, was reportedly placed under investigation for manslaughter and causing the shipwreck.
Speaking to reporters afterwards, one of the captain's lawyers, Giovanni Rizzuti, said: “The captain exercised his right to remain silent for two fundamental reasons. First, he's very worn out. Second, we were appointed only on Monday and for a thorough and correct defence case, we need to acquire a set of data that at the moment, we don't have.”
Tim Parker Eaton is understood to have been in charge of adequately securing the yacht's engine room and operational systems, while Matthew Griffith was on watch duty during the night of the disaster.