Google has dismissed a persistent rumour that a would-be Jacques Cousteau discovered the lost city of Atlantis using the Google Earth mapping program.

The user had discovered a series of lines, resembling a wrecked city grid, deep on the ocean floor about 1,000 kilometres off the coast of Africa.

That led some Google Earth aficionados to posit that the lines were in fact the remains of the lost city of Atlantis, since it was deemed to match the approximate location described by Plato, the ancient Greek philosopher.

For some, however, the theory seemed a little far fetched.

This week, Google was forced to release a statement denying that their wildly popular product had solved an age old quandary - a rare moment for the all-conquering Internet giant.

"It's true that many amazing discoveries have been made in Google Earth, including a pristine forest in Mozambique that is home to previously unknown species and the remains of an Ancient Roman villa," said a Google statement which appeared on the BBC's website.

But Google said the "Atlantis" lines were the result of sonar information collected from vessels sailing the high seas.

"In this case, however, what users are seeing is an artifact of the data collection process. Bathymetric (or sea floor terrain) data is often collected from boats using sonar to take measurements of the sea floor," Google said.

"The lines reflect the path of the boat as it gathers the data. The fact there are blank spots between each of these lines is a sign of how little we really know about the world's oceans."

The original discovery of the grid was attributed to British aeronautical engineer Bernie Bamford, who first spotted the lines last week, London's Sun newspaper reported on Friday morning.

Those reports prompted Charles Orser, curator of historical archeology at the New York State Museum, to tell the paper that the finding merited greater investigation.

Not anymore.

The mystery of Atlantis has mystified historians and regular folk alike since it was mentioned by Plato in his Timaeus and Critias dialogues in about 350 B.C.

Plato said that Atlantis was a naval power that took over large swaths of Europe and Africa in about 9600 B.C.

But Atlantis fell upon hard times and sunk into the ocean after a botched attempt to conquer the ancient Greek city of Athens, Plato said.