“It was a sudden and abrupt event,” said Termini Imerese public prosecutor Raffaele Cammarano, who is coordinating the investigation into the shipwreck.

The other victims were Jonathan Bloomer, chairman of Morgan Stanley International, his wife Anne Elizabeth, Lynch’s lawyer Chris Morvillo, the latter’s wife Nada and chef Recaldo Thomas.

The passengers had no time to escape because they were sleeping in their cabins aboard the superyacht, which was owned by Lynch, the prosecutor said.

The 59-year-old magnate had invited his friends and their families on a cruise to celebrate the successful end of a 12-year legal battle.

The battle was to clear his name linked to the 11-billion-dollar sale of his company, Autonomy, to Hewlett-Packard in 2011.

HP had accused Lynch of deception.

Cammarano, the prosecutor, added that “at the moment we do not have the certainty that there is a black box” and “we cannot confirm whether the hatches were open”.

Bayesian captain James Catfield, 51, a very experienced New Zealand-born sailor, may face charges of negligent manslaughter in failing to allegedly secure the ship.

According to an expert engineer at Italian Sea Group - the company that owns Perini Navi, the shipyard in Viareggio that in 2008 launched the Bayesian - who spoke on condition of anonymity, several mistakes could have been committed ahead of the accident.

Potential mistakes include the fact that the boat’s engines were off and that passengers were allowed to remain in their cabins during the storm.

Cammarano said that the public prosecutor’s office had opened a file against “unknown persons on charges of manslaughter and culpable homicide”.

He apologised for the little information he had been able to give to reporters so far, explaining that under the ‘Cartabia law’, “in Italy you are not allowed to do otherwise”.

Meanwhile, Esme Lynch, 21, remembered her younger sister Hannah by saying, “She is my little angel, my star.”

Hannah Lynch had just won a place at Oxford University.

Those who knew her said she was a model student, a lover of books and poetry, who after graduating high school was preparing to go up to the prestigious university.

“She was a supernova, determined and stubborn,” said one friend.

A fiend of her father called him “one of the most brilliant minds I have ever encountered”.

Lynch’s wife Angela Bacares was among the 15 people rescued.

The yacht’s name came from the Bayesian theory, the basis for Lynch’s PhD thesis and the software that powered his company.

The Lynch family on Friday thanked Italian authorities for their assistance in the tragedy.

“As members of the Lynch family we are devastated, in shock and are comforted and supported by our family and friends,” the said in a statement.

“Our thoughts at this time are with all those affected by the tragedy.

“We sincerely thank the Italian coast guard, the emergency services and all those who contributed to the rescue.

“We now ask that our privacy be respected at this time of untold grief.”

ANSA