An elite Nepalese mountaineer responsible for setting up climbing routes on Mount Everest plunged to his death over the weekend, the first loss of the summit season, an official said Monday.

Mingmar Sherpa, 47, was a member of a team known as the "icefall doctors" who maintain the routes up Everest, setting up ropes and ladders which are used by hundreds of commercial climbers on the world's highest mountain.

He was returning to the team's campsite on Sunday when he slipped and fell to his death in a crevasse, said Gyanendra Kumar Shrestha of the Nepal Tourism Board.

"A helicopter was sent to recover his body but it could not land due to bad weather," Shrestha told AFP.

Last season, six climbers including four in one weekend died, which made it one of the most treacherous years in recent memory and sparked a debate about whether overcrowding was contributing to the death toll.

Approximately 300 people have perished trying to reach the 8,848-metre (29,029-foot) summit in the last 60 years.

Ang Tshering Sherpa, a mountaineering expert, said being an "icefall doctor" was extremely challenging, but it was the first time he had heard of one of them dying.

"The icefalls between Camp One and Camp Two keep moving. So a team of six of them keep watching it and changing the route until they are 100 percent sure," he said.

"It takes them two weeks to complete the set-up," Sherpa said, adding that a Nepalese non-governmental organisation hires the Sherpas for the task.

More than 3,000 people have climbed Everest, which straddles Nepal and China, since it was first conquered by Edmund Hillary and Tenzing Norgay in 1953. Every year hundreds more set out in April to attempt the climb.

The climbing season runs from late April to May which offers the best conditions for making the ascent.