Found, the city hidden by sea

It is the moment to set the heart racing of every would-be Indiana Jones. The discovery of a lost city swallowed by the sea at least 1,500 years ago.

Incredible pictures taken at Mahabalipuram off the south-east coast of India depict what appear to be the ruins of a city from the ancient world.

The pictures were taken by a joint expedition of India's National Institute of Oceanography and the Scientific Exploration Societ with Monty Halls, a former Royal Marines officer, in charge of the team.

Carved stone blocks have been unearthed measuring 30sq ft. It is believed these could have been the foundation stones for a temple shrine. There is also an eroded statue of a lion's head, the classic representation of the god Siva.

The structures are at a depth of between five and seven metres and cover an area of several square miles. Divers - who could only stay submerged for 45 minutes at a time - found that this was not enough to swim to the end of the "ruin field".

Diving the site is a logistical nightmare. Visibility can be as poor as two metres and the region has no dive boats, decompression chambers or hospitals. Despite the strong surf, native fishing vessels have had to be used.

Mr Halls said: "This site is at least 1,500 years old. The fishermen told us lovely stories about their forefathers diving down into the temples and huge wooden doors closing behind them and locking them in."

Tantalisingly, the same fishermen say there are more ruins further out to sea. These could be many years older still. Mr Halls, 35, added: "It was every diver's dream to crash through this gigantic surf in these tiny native fishing boats, hanging on for grim death. We had one turn over in the surf, it was really hairy stuff. But then to jump over the side and see things which we all knew were very, very special.

"Some people have said that everyone has always known there are ruins in the sea off there. If everyone has always known that why has no one explored this colossal set of magnificent ruins? It could be one of the major marine archeaological sites on earth."

At first glance the find seems to corroborate the myth perpetuated by fishermen of a great flood. Legend has it that six temples were submerged beneath the waves with the seventh left standing alone on the shore. The cataclysm was said to have happened because the gods had become jealous of the beauty of the great city.

Bestselling author and adventurer Graham Hancock studied themyths to pinpoint the location of the lost city. In contrast to the orthodox view about the origins of civilisation he believes that the seabed in the Mediterranean and the Indian sub-continent contains many ruins from advanced civilisations.

In Mr Hancock's view these societies were destroyed by the rising waters after the Ice Age ended between 7,000 and 17,000 years ago. If true, they would pre-date the pyramids. Others dismiss his thesis, arguing that such advanced civilisations would have colonised places other than just coastlines.

Mr Hancock said: "If we vigorously pursue obscure flood myths and sightings by local fishermen - a method which is generally dismissed by archaeology - it can lead to archaeological discoveries.

"I'm joyous that a major archaeological discovery has been made as a result of my efforts. At the very least you could say this is the Alexandria of the Indian Ocean. This is a fabulous site and on an enormous scale."