Mountaineer Denis Urubko has quit a dangerous bid to make the first solo winter ascent of K2, the world’s second-highest mountain, a spokesman for his Polish expedition says.
Mr Urubko decided on Sunday to set out alone after a row with the expedition.
He is said to have wanted to make the ascent before the arrival of better weather conditions in March.
Amid concern over his safety, the expedition spokesman said Mr Urubko was now heading down the peak to a base.
Michal Leksinski told the BBC that he expected Mr Urubko to reach base camp by Tuesday morning at the latest.
The Russian-Polish mountaineer is likely to have spent a night at 7,200m (23,600ft) and decided to turn back after experiencing the severe weather conditions, Mr Leksinski added.
He said other climbers on the mountain had seen Mr Urubko descending and reported it to base camp.
It is thought he wanted to reach the top of the mountain this month so his effort would definitely count as a winter climb.
Why did they fall out?
Mr Urubko reportedly left for the summit without a radio, after refusing to discuss his plans.
“He was trying to persuade the team to push for the summit in February,” a porter with the group told AFP news agency.
“He has had a heated debate with the team leader and left for the summit without saying a word.”
How dangerous would a solo bid be?
Professional mountaineers expressed dismay at the climber’s decision.
“A solo attempt of K2 in winter is completely suicidal,” said Pakistani climber Mirza Ali Baig.
Alan Arnette, a US climber who did make it to the summit of K2, told the BBC: “It’s a huge risk. You have to cross a traverse underneath a 30-storey ice serac, a hanging serac of a wall of ice that let loose in 2008 and killed 11 climbers that year.”
Karim Shah, a mountaineering friend of Mr Urubko, agreed the move was “very risky”.
“He is known as the ‘Himalayan expert’ among the mountaineering community. But his decision is not correct and does not suit someone of his stature,” he said.
How good is Denis Urubko?
He is said to be a highly capable mountaineer who has conquered all of the world’s 14 peaks over 8,000m.
Mr Urubko made headlines just last month by saving a stricken French climber, Elisabeth Revol.
He and three other team members were flown by helicopter from K2 to the 8,126m Nanga Parbat in Pakistan – nicknamed Killer Mountain – where they performed an audacious night-time rescue.
K2 stands at 8,611m and is the only peak above 8,000m never climbed in winter.
It has a higher fatality-to-summit rate than Everest, and is known as the Savage Mountain due to its fiendish conditions.
Avalanches are an ever-present risk, and in winter temperatures can fall to -50C (-58F), accompanied by winds of up to 200km/h (124mph).
On 1 August 2008, 11 climbers from international expeditions were killed or simply vanished on K2 – in what was one of the deadliest days in mountaineering history.