First photos released showing 'shark cave' where five tourists died in Maldives scuba tragedy

The first pictures of the underwater cave where five Italian divers died have been made public, as four of their bodies were repatriated to Milan on Saturday for Italian prosecutors to advance their manslaughter investigation.

The photos were taken by one of the elite Finnish divers called in to recover the remaining victims, after the one of the Maldives National Defense Forces' search rescuers died during a dive.

The five Italians vanished on May 14 during a deep-water dive inside a cave 164 feet underwater in Vaavu Atoll, in what officials called the worst diving accident in the island nation's history. Finnish diver Sami Paakkarinen, who was part of the recovery team, revealed the group were just 15 minutes from the surface when they died, and were not carrying the equipment they needed to survive.

"Unfortunately, in most cave diving accidents, the main cause is always human error," Paakkarinen said.

A prosecutor's office in Rome has opened a culpable homicide investigation into why the group of experienced divers descended below the Maldives' legal recreational diving limit of 100 feet without the required training, permits or equipment.

This image shows the mouth of the cave where the divers dissapeared, with sunlight still visible (DAN EUROPE)

The first set of images, taken near the mouth of the cave, shows the sunlight still lighting the way. That's where diving instructor and boat captain Gianluca Benedetti was found, away from the rest of the group, on the day of the tragedy.

Benedetti is believed to have tried to find his way out of the cave before he ran out of air and died near the entrance.

Images show slightly reduced visibility as you get deeper into the cave (DAN EUROPE)

But in a second set of photos taken deeper inside the cave, the conditions tell a very different story. Visibility is drastically reduced, here, a small kick of the fins as divers try to move through the tight space is enough to stir up sediment from the ocean floor, clouding the view entirely.

That's where the group is believed to have become disoriented, eventually running out of air.

What went wrong in the Maldives dive?

According to Paakkarinen, the group entered the cave without proper cave diving equipment, most critically, a diving reel or guide rope, which is considered essential for navigating underwater cave systems safely.

"The equipment we found them with wasn't optimal, they weren't using underwater caving gear," he said.

"In general, for those who visit caves, it's known that it's not very wise to do so without a safety line."

Without a guide rope, disorientation in an underwater cave can be fatal. There is no way to retrace your route, no reference point back to open water.

The cave was made up of three large chambers connected by narrow passages. Investigators believe the group may have taken a wrong turn into a dead-end corridor, the same corridor where four of the five bodies were eventually found together, 200 feet below the surface.

Just a small kick of the fins can reduce visibility quickly, and drastically (DAN EUROPE)

Making matters worse, the boat they were diving from had permission only for dives of up to 30 metres, and divers were briefed on arrival about that limit. The group descended to nearly double that depth.

The Italian tour company that sold trips on the yacht said its operator "did not know" the group planned to go deeper than the recreational limit and "would never have allowed it."

Authorities in the Maldives have since suspended the Duke of York liveaboard's operating licence indefinitely, pending the outcome of the investigation.