The ruins, which are off the coast of Mahabalipuram, cover many square miles and seem to prove that a major city once stood there.

A further expedition to the region is now being arranged which will take place at the beginning of 2003.

'International significance'

The discovery was made on 1 April by a joint team of divers from the Indian National Institute of Oceanography and the Scientific Exploration Society based in Dorset.

Expedition leader Monty Halls said: "Our divers were presented with a series of structures that clearly showed man-made attributes.

"The scale of the site appears to be extremely extensive, with 50 dives conducted over a three-day period covering only a small area of the overall ruin field.

"This is plainly a discovery of international significance that demands further exploration and detailed investigation."

During the expedition to the site, divers came across structures believed to be man-made.

One of the buildings appears to be a place of worship, although they could only view part of what is a huge area suggesting a major city.

Jealous Gods

The myths of Mahabalipuram were first set down in writing by British traveller J. Goldingham who visited the South Indian coastal town in 1798, at which time it was known to sailors as the Seven Pagodas.

The myths speak of six temples submerged beneath the waves with the seventh temple still standing on the seashore.

The myths also state that a large city once stood here which was so beautiful the gods became jealous and sent a flood that swallowed it up entirely in a single day.

One of the expedition team, Graham Hancock, said: "I have argued for many years that the world's flood myths deserve to be taken seriously, a view that most Western academics reject.

"But here in Mahabalipuram we have proved the myths right and the academics wrong."

Scientists now want to explore the possibility that the city was submerged following the last Ice Age.

If this proves correct, it would date the discovery at more than 5,000 years old.