Swiss climber Ueli Steck, one of the most feted mountaineers of his generation and famed for his speed ascents of iconic Alpine routes, has died on Everest, 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.
Steck, 40, was on Everest to acclimatise before attempting to summit the world's tallest peak in May, using a never before climbed route.
"He skidded off about 1,000 metres from (Everest) camp two early morning on Sunday. Other climbers ascending Everest saw him and asked for his rescue," said Dinesh Bhattarai, director general at the Department of Tourism.
The accomplished alpinist sought to pioneer new routes throughout his mountaineering career, earning the nickname "the Swiss Machine" for his solo record ascents in the Alps.
Steck hit global headlines in 2013 when he and two other Western climbers traded blows with a group of furious Nepali guides over a climbing dispute on Mount Everest.
An angry Steck swore never to return to Everest, telling a Swiss website that his "trust (was) gone".
The brawl shocked the mountaineering community, causing a damaging rift between Western climbers and the often lowly-paid Nepalese guides who are essential for commercial expeditions to the crowded summit.