Italian officials are scheduled to hold a press conference on Saturday morning on the sinking of a luxury yacht off the coast of Sicily.

On Friday, 18-year-old Hannah Lynch became the final missing passenger to be recovered from the wreckage of the Bayesian superyacht.

The discovery comes as unconfirmed reports in the Italian media have said that prosecutors are set to announce a manslaughter investigation into the incident.

Termini Imerese Public Prosecutor’s Office investigators said it will hold a news conference to unveil the first findings of its criminal investigation, which was opened immediately after the tragedy despite no formal suspects having been publicly identified.

The main question investigators are focusing on is how a sailing vessel deemed “unsinkable” by its manufacturer, Italian shipyard Perini Navi, sank while a nearby sailboat remained largely unscathed.

Hannah and her father Mike Lynch, alongside Morgan Stanley International bank chairman Jonathan Bloomer, his wife Judy Bloomer, Clifford Chance lawyer Chris Morvillo and his wife Neda Morvillo were lost when the yacht sank at around 5am local time on Monday.

In a statement, the family of Mr Lynch and Hannah said: “The Lynch family is devastated, in shock and is being comforted and supported by family and friends.

“Their thoughts are with everyone affected by the tragedy.

“They would like to sincerely thank the Italian coastguard, emergency services and all those who helped in the rescue.

“Their one request now is that their privacy be respected at this time of unspeakable grief.”

The Lynch family also issued a photograph of Mr Lynch and Hannah alongside their tribute.

Hannah’s sister Esme paid her own tribute, saying: “Hannah often burst into my bedroom and lay down with me.

“Sometimes beaming with a smile, sometimes cheeky, sometimes for advice.

“No matter what, she brought boundless love to me.

“She was endlessly caring, passionately mad, unintentionally hilarious and the most amazing, supportive and joyful sister and best friend to me.

“And on top of all this, she had even more love to give endlessly to all her friends and passion to give to her incredible studies and goals.

“She is my little angel, my star.”

Vincenzo Zagarola, of the Italian Coastguard, said the search for Hannah was not “easy or quick”, comparing the sunken yacht to an “18-storey building full of water”.

The bodies of all six missing passengers have now been brought to shore in the small fishing village of Porticello, around 11 miles from the Sicilian capital of Palermo.

Of the 22 passengers and crew on board, 15, including Mr Lynch’s wife, Angela Bacares, were rescued after escaping on to a lifeboat.

The body of Canadian-Antiguan national Recaldo Thomas, who was working as a chef on the superyacht, was recovered at the scene of the sinking on Monday.

The boat trip was a celebration of Mr Lynch’s acquittal in a fraud case in the US.

The businessman, who founded software giant Autonomy in 1996, was cleared in June of carrying out a massive fraud relating to its 11 billion dollar (£8.64 billion) sale to US company Hewlett Packard.