Swiss climber Ueli Steck, famed for pioneering new mountaineering routes and setting speed records, was found dead on Mount Everest on Sunday morning, officials said.

"Today morning, he had an accident on the Nuptse wall and died. It seems he slipped," Ang Tsering Sherpa, head of the Nepal Mountaineering Association, told AFP.

Mingma Sherpa of the Seven Summit Treks said Steck was killed at Camp 1 of Mount Nuptse. His body has been recovered from the site and been taken to Lukla, where the only airport in the Mount Everest area is located.

It was not clear how Steck died but he was planning to climb 8,850-meter (29,035-foot) Mount Everest and nearby Mount Lhotse next month.

He was the first casualty in the spring mountaineering season in Nepal that began in March and will end in May. Hundreds of foreign climbers are on the mountains to attempt scale Himalayan peaks in May when there are a few windows of favorable weather on the mountains.

The 40-year-old Steck was one of the most-renowned mountaineers of his generation.