The family of Mike and Hannah Lynch, who died after a luxury yacht sank off the coast of Sicily, have said they are “devastated” and “in shock”.

On Friday, 18-year-old Hannah 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.

The pair, 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.

One of Hannah’s former teachers paid tribute to her after her body was recovered from the wreckage, saying: “I will remember her for what she taught me: kindness, compassion and commitment.”

Jon Mitropoulos-Monk, head of English at Latymer Upper School in Hammersmith, said: “I’ve never taught someone who combined sky-high intellectual ability with warmth and enthusiasm in the way Hannah did.”

Her friend Katya Lewis also paid tribute, saying: “Being with Hannah made me feel whole and happy.

“She is the most special friend anyone could ask for and I will always love Hannah.”

In a statement confirming their parents’ deaths, the Bloomer family described the couple as “incredible people and an inspiration to many”.

Mr Zagarola previously said a decision on whether to raise the sunken yacht from the seabed is “not on the agenda”, but will be in the future.

The luxury yacht’s captain, James Cutfield, has reportedly been questioned by authorities in connection with the sunken vessel.

A helicopter, remotely controlled underwater vehicles, naval units and cave divers were used during the search operation.

Bayesian was moored around half a mile off the coast of Porticello when it sank as the area was hit by a storm.

The wreckage of the superyacht is resting on the seabed off the coast at a depth of 50 metres (164ft).

Prosecutors in the nearby town Termini Imerese are scheduled to hold a press conference on Saturday morning.