A top mountaineer has died while descending the 7,234-metre peak of Langtang Lirung in Nepal, after completing the rare feat of successfully scaling its dangerous eastern face.

Slovakian Ondrej Húserka had been scaling the mountain with partner Marek Holeček when he when he fell into a crevasse on October 31.

Mr Holeček detailed the death of his partner on Facebook, saying Mr Húserka's rope broke while he was rappelling down, propelling him into an eight metre drop, before he fell further into the "depths of the glacier".

He said he stayed with Mr Húserka for four hours until he died in his arms, noting he believed he had broken his spine and become paralysed.

"His star was fading as he lay in my arms … it lasted hours," he wrote.

The Slovak climbers' association, SHS James, said bad weather had delayed rescued helicopters from retrieving Mr Húserka's body.

"Humble and great friend, top mountaineer, it is not an exaggeration to say world-class, gone prematurely," it said in a Facebook statement.

The duo had previously climbed the east face of the mountain for five and a half days.

Langtang Lirung, which lies around 50 kilometres north of Nepal's capital Kathmandu, is considered to be extremely prone to avalanches and rockfalls.

Mr Húserka was considered one of the best climbers in Slovakia.

He joined the Slovak national alpinism team in 2011 and won the SHS James best ascent of the year award six times, according to his website.

ABC