The diving instructor of the Italians who died in sea caves in the Maldives was discovered in a separate location to the four others who perished, in a search operation on Monday.

Tragedy struck on Thursday after five - including a mother and daughter - died while attempting to explore caves at a depth of around 165ft, in the worst single diving accident in the history of the tiny Indian Ocean nation.

The body of one of the group, instructor Gianluca Benedetti, was recovered from the mouth of the Thinwana Kandu cave, also known as Shark Cave, on Friday, at a depth of around 197ft.

It wasn't until Monday that a team of three elite Finnish divers were able to locate the rest of the group, and discovered them at the end of a tunnel - deep at the bottom of the cave's second chamber.

The cave is divided into three large chambers connected by narrow passages, two of which were explored on Friday, but the perilous search was initially limited due to considerations over oxygen and decompression. 

An initial search operation for the victims ended in tragedy on Saturday when Maldivian military rescue diver Mohamed Mahudhee was admitted to hospital and died from decompression sickness after assisting in the recovery effort.

As well as Benedetti, the other victims of the diving group have been identified as Monica Montefalcone, an associate professor of ecology at the University of Genoa; her daughter, Giorgia Sommacal; marine biologist Federico Gualtieri and researcher Muriel Oddenino. 

The Italian tour operator that managed the diving trip has denied authorising or being aware of the deep dive that violated local limits, its lawyer told Italian daily Corriere della Sera on Saturday.

Orietta Stella, representing Albatros Top Boat, said the operator 'did not know' the group planned to descend beyond 30 meters. 

That threshold requires special permission from Maldivian maritime authorities, and the tour operator 'would have never allowed it,' she said.

The dive far exceeded what was planned for a scientific cruise focused on coral sampling at standard depths, Stella added.

The victims were experienced divers, but the equipment used appeared to be standard recreational gear rather than technical equipment suited for deep cave excursions, she said. 

The expert Finnish divers - Sami Paakkarinen, Jenni Westerlund and Patrik Grönqvist - worked alongside the MNDF and other officials in the rescue mission.

Following the death of rescue diver Sergeant-major Mahudhee during Saturday's search operation, the MNDF temporarily suspended the recovery effort, which has been taking place in rough weather and sea conditions.

'The death goes to show the difficulty of the mission,' the Maldives' presidential spokesman, Mohamed Hussain Shareef, said.

The Maldivian military added in an X post: 'His courage, his sacrifice, and service to the nation will always be remembered.

'Our deepest condolences to his family and colleagues.'

Shareef said the searchers had prepared a plan based on their progress exploring the cave on Friday.

Shareef said Benedetti's body was found near the mouth of the cave, and authorities believed the remaining four had entered it.

The Italian Foreign Minister, Antonio Tajani, said everything possible would be done to bring the victims home.

His ministry stated it was coordinating with Divers Alert Network, a specialist diving organisation, to support recovery operations and the repatriation of the bodies.

However, the mystery continues to surround the cause of death. 

Authorities have launched an investigation to understand what happened, while several theories are being considered.

Montefalcone, 51, was a respected marine biologist, TV personality, and professor of Tropical Marine Ecology and Underwater Science at the University of Genoa. Her daughter, Giorgia, was 22 years old.

Montefalcone's husband and Giorgia's father, Carlo Sommacal, said on Friday that footage taken on a GoPro camera could reveal the mystery surrounding their deaths.

Speaking to Italian news outlet La Repubblica, a devastated Sommacal said: 'Monica usually had a GoPro when she went diving.

'I don't know if she had one the other day. If they find it, maybe from there we can understand what happened.'

He also insisted that 'my wife [was] among the best divers on earth,' and said she wouldn't have put anyone in the group in danger.

'She would never have put our daughter's life or that of others at risk... something must have happened down there,' he said.

'Maybe one of them had trouble, maybe the oxygen tanks, I have no idea.'

Montefalcone had survived the 2004 Boxing Day tsunami when it struck the Maldives. 

Sommacal added that one of the divers on the expedition, Benedetti, was 'meticulous.'

'He checked everything: the tanks, the weather conditions. He's not a fool,' Sommacal said. 'It must have been fate; they took every precaution possible.'

The grief-stricken father revealed that his daughter Giorgia was going to graduate from university next month and said he and his wife had been planning a party for her.

Victim Oddenino, a 31-year-old marine biologist and ecologist, was Montefalcone's colleague.

She was an experienced diver and authored scientific publications. She was described by a loved one as 'sweet and sensitive'.

Benedetti, 44, was an operations manager, a diving instructor and a boat captain.

After working in banking and finance for several years, he turned his passion for diving into a full-time career and moved to the Maldives in 2017.

He was the operations manager and skipper aboard the luxury Duke of York, the diving yacht that the group used for their expedition.

He was described by Albatros Top Boat, the Duke of York's operator, as 'energetic, extremely sporty, and a lover of reading, classic cinema, and chess.'

Speaking about her son's death, Benedetti's mother told Italian news outlet Gazzettino: 'I heard the news from the embassy. I can't say anything, and you can only imagine the pain.'

Gualtieri, 31, was a scuba diving instructor and had recently graduated from the University of Genoa with a degree in marine biology and ecology.

He had previously praised his professor, Montefalcone, saying: 'Ever since I met her, she has always been my guide, encouraging me to follow my dreams and passions.'

Cave diving is a highly technical and dangerous activity that requires specialised training, equipment and strict safety protocols.

Risks increase sharply in environments where divers cannot head straight up and at depth, particularly when conditions are poor.

Experts say it is easy to become disoriented or lost inside caves, particularly as sediment clouds can sharply reduce visibility.

Diving at 50 meters also exceeds the maximum depth recommended for recreational divers by most major established scuba certifying agencies, with depths beyond 40 meters considered technical diving and requiring specialised training and equipment.

Shareef said that the cave 'is so deep that even divers with the best equipment do not try to approach.'

'There will be a separate investigation into how these divers went below the permitted depth, but our focus right now is on the search and rescue,' he added.

Authorities have not ruled out several scenarios, with police probing whether bad weather may have affected the divers' visibility.

According to Italian news outlet La Repubblica, the fact that none of the five divers managed to resurface suggests the group may have become lost within an underwater cave.

With little light and poor visibility due to bad weather, they may have lost their bearings, panicked, and perhaps run out of air while trying to find their way out.

Police also haven't ruled out the possibility that one of the five may have become stuck while the others ran out of air or panicked trying to free their colleague.

Diving experts have also been speculating on various hypotheses.

According to local media, one of the most widely accepted hypotheses by the coast guard and experts is oxygen toxicity. 

This phenomenon occurs if the tank's mixture is inadequate, making oxygen toxic at certain depths.

'At 50 meters of depth in the sea, there are several risks; it's a real tragedy,' says Alfonso Bolognini, president of the Italian Society of Underwater and Hyperbaric Medicine.

'There are several hypotheses we can make right now: an inadequate breathing mix can create a hyperoxic crisis when there's an increase in the partial pressure of oxygen in the tissues and blood plasma, which can cause neurological problems.

'Inside a cave at 50 meters of depth, all it takes is a problem for a diver or a panic attack for a diver,' he adds, saying that 'the agitation causes the water to become cloudy and can impair visibility.

'In these cases, the panic component could lead to even fatal errors.' 

It is also unclear whether the Italians' dive, being at a depth of over 160ft, was regulated, according to the Maldives National Defence Force.

Meanwhile, it has been revealed that there was no local guide to accompany the group into the cave, as required by Maldivian law.

Investigators are also trying to determine whether the group used an 'Ariadne's thread' - a rope used by divers while exploring caves to help them stay close together and find the entrance and exit to the cavities.

The use of the rope is mandatory in certain caves.

The Maldives, a nation of 1,192 tiny coral islands scattered some 500 miles across the equator in the Indian Ocean, is a luxury holiday destination popular with divers, who often stay at secluded resorts or on dive boats.

Local regulations allow dives to a maximum depth of 98 feet, but experienced professionals are known to go deeper.

Diving and water-sport-related accidents are relatively rare in the South Asian nation, although several fatal incidents have been reported in recent years.