Eric Simonson with Mallory's goggles

Mallory, and his colleague Andrew "Sandy" Irvine, disappeared while attempting to be the first to climb the world's highest mountain in 1924.

Mallory's body was found by a US-led expedition in early May, 600m from the summit.

Conrad Anker, a member of the Seatle-based Mallory & Irvine Research Expedition, told a news conference on Tuesday he doubted the 1924 team had managed to conquer the 8,848m mountain.

"I think it is improbable they made it to the summit," he said, blaming technical difficulties on the last leg of the climb.

Split decision

But another member of his team, Andy Politz, from Columbus, Ohio, disagreed.

He said: "I still think they made it to the top," but added there was no evidence to back his feeling.

After the discovery of Mallory's almost perfectly preserved body, it had been hoped that the body of Irvine, with the camera he was known to have been carrying, might be found.

It is believed possible that the mountain's freezing temperatures may have preserved the film, which could provide photographic evidence of a conquest.

But expedition leader Eric Simonson, from Ashford, Washington, said the team had failed to find either.

Return to Everest

The team displayed other objects they had recovered, such as a handwritten letter, Mallory's goggles, a knife and his oxygen bottle.

The team did not reveal the contents of the letter, but said it was "a fascinating relic".

The finds are being donated to an American mountaineering organisation, who may pass them on to Mallory's family.

The Everest mystery may yet be solved, however, as the team intend to return to the mountain to search again for Irvine's body and the camera.

Mr Simonson said: "George Mallory is now buried. There is no reason for anyone to go back to him.

"He can rest in peace."

New Zealander Sir Edmund Hillary and his Nepalese guide, Sherpa Tenzing, are universally accredited with reaching the summit of Everest first, in 1953.