Climbers unable to confirm Everest achievement

An expedition on Mount Everest retracing the 1924 climb by George Mallory and Andrew Irvine returned from the mountain today unable to say whether the two men were the first to scale the world's highest peak.

Climbers from the Altitude Everest Expedition 2007 returned to the Nepalese capital Kathmandu today after reaching the 29,035-foot summit from the Chinese side of the mountain in the north and filming a documentary.

The expedition wanted to get closer to answering Mount Everest's long-held secret - whether the two Britons reached the summit 29 years before New Zealander Edmund Hillary and Nepalese Sherpa Tenzing Norgay successfully scaled the mountain on May 29, 1953.

"I still believe the possibility is there they made it to the top but it is very unlikely," said American climber Conrad Anker, 44, of Bozeman, Montana, who reached the summit on June 14.

The team filmed a documentary investigating Mallory and Irvine's last journey as they tried to reconstruct their final, fateful hours.

There has been speculation for years that Mallory and Irvine may have conquered Everest but died on the way down.

So far there has been no proof, and mountaineering community and history books recognise Hillary and Norgay's climb as the first to the top of the world.

"There is no question that the first ascent of Mount Everest occurred in 1953. You have to get to the top and then return safe and sound," Anker said. "The possibility is there and they had the skills they could have done it. But if they had made it the summit, they did not return so it's not a valid ascent."

During some parts of their climb, team members also wore similar clothing and equipment used by the Mallory and Irvine in an attempt to mimic the 1924 climb.

The 1924 climbers used wool, silk and leather equipment, considered insufficient compared to the high-tech synthetic gear used by modern-day climbers.

Anker discovered Mallory's frozen body in 1999 during a similar expedition. That expedition also recovered hand-written letters addressed to Mallory, goggles, an altimeter, a pocket-knife and a piece of rope, but did not find a camera the climbers were believed to be carrying.

Unable to remove Mallory's body, the team buried it under rocks.

Mallory and Irvine were last seen just 900 feet from the summit in 1924. Irvine's body has never been found.