FOUR people died becoming trapped in a submerged cave near the tourist Italian port of Palinuro at the weekend the coastguard revealed.

Douglas Rizzo, who was born in London but had been living in Rome, is believed to have been the leader of a party of divers who lost their bearings after kicking up mud from the floor of the "Blood Grotto", a popular destination with amateur divers because of its red walls, caused by a bacterial growth.

According to Italian investigators the group missed the exit to the cave after becoming confused and instead entered a nearby tunnel which led to a chamber with a dead end.

An Italian magistrate has opened an inquiry into the accident at the seaside resort south of Naples. Authorities identified the victims as Rizzo, 41, who leaves a wife and six-month old son, Andrea Pedroni, 40, from Rome, Greek-born Panaiotis Telios, 23, from Reggio Calabria, and Susy Covaccini, 36, also from Rome.

Massimo Ruggiero, the coastguard commander in Palinuro, said: "The entrance to the cave is through a tunnel at a depth of 13 to 14 metres. The group should then have swum up to a higher tunnel and made their exit from the cave through that.

"Beneath this channel there is another tunnel that leads to a dead end in a chamber with a sandy floor. All the victims were found there."

Marco Sebastiani, one of four other divers who survived the tragedy said he realised something was wrong when he saw their guide showing signs of agitation, but at that point it was too late.

"We suddenly found ourselves in a blind tunnel. We couldn't see anything. At that point it was panic. The agitation of the least experienced took hold. Mud and sand came up from the bottom of the cave and visibility was gone," Mr Sebastiani told Il Messaggero newspaper.

"At a certain point I managed to find my way. I took as many people as I could with me and we swam towards the light, which grew bigger all the time. When I came up, I looked around to count us and I realised that Susy, Andrea, Douglas and Panos weren't there."

Roberto Navarra, the diving school owner who provided the group's equipment, confirmed yesterday (Sunday) that four of the group had swum into the wrong tunnel.

"It's an easy cave but there is a dangerous tunnel that people never use. Four people swam into that channel," Mr Navarra told reporters.

He said he had tried repeatedly to save the missing divers but "the visibility was terrible. You could see nothing".

Mr Navarra said the group was correctly equipped and carried torches. "Unfortunately there was not one, but an incredible series of negative circumstances. Now we are all shocked and saddened."

Valter Ciociano, an expert diver from nearby Marina di Camerota, said many of the 35 underwater caves that draw divers to the area have muddy bottoms. "Often when you go in, the water is clear and you don't notice that your flippers are muddying the water behind you, creating what seems an impenetrable wall. On these occasions it's panic that rules the day."

The underwater caves do sometimes contain small air pockets under the roof, but experts say they are no guarantee of safety. In many cases the air would not be breathable because of the presence of poisonous hydrogen sulphide fumes.

Telegraph.co.uk