After a decade of intense study an American, Robert Sarmast, claims to have assembled evidence to prove that the fabled island lies a mile deep in the sea between Cyprus and Syria.

He says he has detected "around 48" of the 50 geographical features described by Plato before it was "swallowed up by the earth".

By August he hopes to have proved that Atlantis was not simply a figment of the imagination but a real empire with stone temples, bridges, canals and roads.

"What we have discovered is a hidden landmass that fits Plato's famed description almost exactly," he said in the Cypriot port of Limassol.

"For the first time we've been able to match that description with a real place which does, I think, prove what the ancient world believed, that Atlantis was founded in history and not a myth."

That the seafaring civilisation should have been located between Greece and Egypt made "perfect sense," he said, since these were the lands where the story originated.

In his dialogues Timaeus and Critias, Plato describes how Atlantis, "an island greater in extent than Libya and Asia", sank under the water in about 9600BC.

It had "soil the best in the world, an abundance of water, and in the heaven above an excellently attempered climate." Its citizens were so blessed under the rule of its 10 princes that few, if any, were compelled to do physical work.

Mr Sarmast, who has been fascinated by Atlantis since boyhood, built on the research of Russian and Israeli scientists who found the stretch of sunken land off the Cypriot coast in 1989.

With the aid of animation software he studied the underwater area with a degree of resolution far greater than previously possible.

"We now know that the Mediterranean is one of the most geologically active areas in the world and that at one time it experienced the "epochal flood" that Plato describes," he said.

Angela Henderson, a British member of the team, said: "It'd be the single most important archaeological discovery in history."

But an archaeologist who asked that her name should not "be associated" with the clamour said: "This is not archaeology. As far as we're concerned this is just another ridiculous claim."

In recent years Atlantis is said to have been found off the Azores, the Americas, Crete, Santorini and Antarctica.