James Cutfield was questioned for more than two hours after the deaths of tech tycoon Mike Lynch, 59, his daughter Hannah, 18, and five others.
Prosecuting magistrates, who spoke to the New Zealander for the second time in a week, said that he had been "extremely co-operative" in answering questions.
Investigators may also interview a crew member who was on watch and survived when the storm hit off Porticello, the Italian press reported.
In Italy being placed under investigation does not imply guilt and does not mean formal charges will follow.
Key crew members have stayed in Sicily voluntarily to help authorities.
Six passengers and chef Recaldo Thomas died when the British-flagged vessel capsized in a freak storm on August 19. The 184ft-long yacht, which had the world's tallest aluminium mast at 246ft, is thought to have been hit by a "downburst".
Diese Geschichte stammt aus der August 27, 2024-Ausgabe von Daily Express.
Starten Sie Ihre 7-tägige kostenlose Testversion von Magzter GOLD, um auf Tausende kuratierte Premium-Storys sowie über 8.000 Zeitschriften und Zeitungen zuzugreifen.
Bereits Abonnent ? Anmelden
Diese Geschichte stammt aus der August 27, 2024-Ausgabe von Daily Express.
Starten Sie Ihre 7-tägige kostenlose Testversion von Magzter GOLD, um auf Tausende kuratierte Premium-Storys sowie über 8.000 Zeitschriften und Zeitungen zuzugreifen.
Bereits Abonnent? Anmelden
Putin Warns Biden Risks Nato At War With Russia
PRESIDENT Joe Biden has authorised Ukrainian forces to use US missiles to strike targets deep inside Russia, Washington officials claim.
Raducanu and Boulter put Brits close to final say
EMMA RADUCANU and Katie Boulter blew away defending champions Canada to help Great Britain reach the Billie Jean King Cup semi-finals.
RATTLED GATLAND FEARS THE WORST
Wales job is on line after a record 11th straight defeat
Robbie and Pamela's all white night out
EVERYTHING was all white on the night for Robbie Williams and Pamela Anderson as they hit the red carpet in LA.
Rape suspects' plea plot to avoid justice
Delaying tactic means more victims pull out, says CPS head
Ruth heads Down Under... but for a TV spin-off show
PRESENTER Ruth Langsford is jetting Down Under following her marriage break-up from Eamonn Holmes to front a spin-off of I'm A Celebrity.
'I canoe it!'...canny Coleen hits jackpot
COLEEN Rooney battled it out in a canoe task in the first episode of I'm A Celebrity while some of her campmates had to tuck into a horrific drink.
PM rebukes Streeting for repeated opposition to assisted dying
SIR Keir Starmer has criticised Health Secretary Wes Streeting for his public interventions against the legalisation of assisted dying in England and Wales.
Hunt for husband after wife found dead in boot
POLICE have launched an international manhunt for the husband of a woman found dead in the boot of a car.
Trump eyes Rwanda deportations
DONALD Trump is considering adapting the Rwanda scheme that Sir Keir Starmer dumped.