The body of a fifth missing person has been recovered from the wreckage of a luxury yacht which sank off the coast of Sicily as the hunt for the remaining passenger continues.

A fire service boat with flashing blue lights returned with a blue body bag to the port of Porticello just after 8.45am local time on Thursday.

Six people, including technology tycoon Mike Lynch, were unaccounted for after the vessel – named Bayesian – sank at around 5am on Monday.

Salvatore Cocina, the head of Sicily’s civil protection agency, confirmed that the fifth body had been recovered on Thursday, following the recovery of four others on Wednesday.

Identities of the bodies have not been confirmed by authorities, despite local and international media reporting some had been identified.

Searches resumed on Thursday morning, with Mr Cocina saying there will be an investigation in due course, but the priority is finding the final missing passenger.

Among those also named as missing were Mr Lynch’s 18-year-old daughter Hannah; Morgan Stanley International bank chairman Jonathan Bloomer; his wife, Judy Bloomer; Clifford Chance lawyer Chris Morvillo; and his wife, Neda Morvillo.

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.

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 captain of another yacht, the Sir Robert BP, who helped to rescue them, said those on board his vessel had spotted the distress flare set off from a life raft.

Karsten Borner said his crew noticed the Bayesian had disappeared before a passenger spotted the flare.

He told Sky News: “We couldn’t see them any more and they disappeared from the radar, we were busy keeping our own ship sailing.

“We couldn’t see the ship again so we were aware something was very wrong.”

He said it was only when the tender set out that they found the life raft.

Mr Borner continued: “It turned out to be the life raft, a 12-person life raft with 15 people inside including one baby.

“They stepped over to our tender and we brought them back to our ship. There we took good care of them, gave them dry clothes, towels, blankets, tea and coffee and so on, and took care of them.”

One of the survivors, British tourist Charlotte Emsley, held her one-year-old daughter, Sofia, above the waves to stop her from drowning.

Dr Domenico Cipolla, of Di Cristina Children’s Hospital in Palermo where the mother and child were taken, told the PA news agency: “The child and the mother went to the hotel near Porticello on Tuesday, they are both in a good condition.

“Obviously the mother and the husband were so shaken by what has happened, it was a tragedy for them.

“She told me that, two minutes after falling asleep with her baby, they were in the water, she did not understand how this happened, it went dark.

“Her partner was not with her, he was in another room.

“She held the child high in her arms above the waves – for a few seconds the baby was in the water but she saved her.

“She sometimes cried for her friends in the hospital.”

A team of four British inspectors from the Marine Accident Investigation Branch (MAIB) arrived in Porticello on Wednesday to look at the site of the sinking.

The Italian Coastguard said the MAIB is not involved in the search for the missing people, and it has not been requested to assist.

The ship’s captain, James Cutfield, was reportedly questioned by authorities for two hours as they began speaking to all crew members.

A helicopter was previously drafted in to help the search effort, and divers from the local fire service have been seen entering the water with torches attached to their headgear.

Fire crews from the Vigili del Fuoco said they have been accessing the vessel through natural entrances, without making openings.

Remotely controlled underwater vehicles have been used, with naval units and cave divers also taking part in the search, the Italian Coastguard has said.

Bayesian was moored around half a mile off the coast of Porticello when it sank at about 5am local time on Monday as the area was hit by a storm.

Vincenzo Zagarola, of the Italian Coastguard, previously said the missing tourists were feared dead.

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

Fire crews described the operation as “complex”, with divers limited to 12-minute underwater shifts.

Survivors have been recuperating at a hotel complex in Porticello, where authorities were gathering witness statements.

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 US dollar (£8.64 billion) sale to US company Hewlett Packard.

The Financial Times reported that Mr Bloomer appeared at trial as a defence witness for Mr Lynch, while media reports suggest the pair are close friends.

In a separate incident, Mr Lynch’s co-defendant in his US fraud trial, Stephen Chamberlain, died after being hit by a car while out running in Cambridgeshire on Saturday.