Divers scouring the wreck of the luxury yacht that sank off the coast of Sicily on Monday have found the bodies of five of the six missing passengers.

The UK tech entrepreneur Mike Lynch, his teenage daughter Hannah Lynch, the Morgan Stanley International chair, Jonathan Bloomer, his wife, Judy, and the Clifford Chance lawyer Chris Morvillo and his wife, Neda, have been missing since the vessel went down on Monday morning.

The 56-metre yacht, named Bayesian and sailing under a British flag, was carrying 22 people and had anchored just offshore near the port of Porticello when it was hit by what was believed to be a tornado or waterspout.

The body of the yacht’s chef, Recaldo Thomas, was located shortly after the vessel sank.

On Wednesday afternoon rescue authorities found the bodies of five of the missing people.

The director-general of Sicily’s civil protection agency, Salvo Cocina, confirmed that four bodies had been recovered by divers, with the fifth having been found but not yet brought back to shore.

Cocina said: “On behalf of myself and my colleagues, I would like to express my deepest sympathy to the families of the victims and express our condolences to them at this difficult time.”

The Italian coastguard was working to confirm the identities, with sources telling the Guardian that Bloomer and Morvillo had been confirmed as among those recovered. One body remained unaccounted for.

On Wednesday evening, Cocina told the PA news agency that the search was being suspended for the night and would resume on Thursday morning.

The bodies will be transferred to the morgue in Palermo, where postmortems will be carried out under the supervision of the public prosecutor of the town of Termini Imerese, who has begun an investigation into the incident.

Some UK media were also reporting that two of the bodies were those of Lynch and his daughter. The Guardian has not been able to independently verify this and there has been no formal confirmation from the authorities.

Body bags were seen being brought into the harbour onboard a fire brigade boat and lifted up on to the quayside.

The search has been challenging for the rescue teams, who have struggled to get to the yacht’s hull. Once they breached the hull further investigation was obstructed by furniture and debris.

Investigators said the operation had been made more difficult by the confined space inside the vessel. Once they had prised open the hull with a hydraulic jack, divers had to insert iron strips sourced from a local blacksmith to wedge the gap open.

As well as deploying divers, the coastguard confirmed it was using a remotely operated vehicle to scour the seabed and collect photographic evidence of the wreckage.

At Porticello harbour, a crowd that had been growing during the course of the day looked on in silence with some shedding tears as the bodies were brought ashore.

Investigators have been questioning witnesses and survivors, with the yacht’s captain, James Cutfield, 51, reportedly interviewed for more than two hours. Cutfield’s brother Mark told the New Zealand Herald he was a “very good sailor” who was “very well respected” in the Mediterranean.

The port authority has opened a separate investigation from that of the public prosecutor in Termini Imerese to determine whether all adequate safety measures were taken by the crew.

The UK’s Marine Accident Investigation Branch said it was also investigating the incident.

A spokesperson said: “The MAIB is investigating the foundering of the UK registered large yacht Bayesian off the northern coast of Sicily on 19 August. It would not be appropriate for the MAIB to comment further while the investigation is ongoing.”

The investigation, which will lead to a report being published on the incident in due course, will look at all relevant aspects, including the design, stability and operation of the vessel. It will also examine the effects of the weather conditions.

The former cabinet minister Lord Deben said Lynch, his friend, was at the “beginning of a new life” when his boat capsized in the violent storm.

Deben, the former Conservative MP John Gummer, said Lynch had been preparing for a fresh start after being cleared in June of fraud charges in the US relating to the purchase of his company, Autonomy, by Hewlett-Packard in 2011.