Paintings of Buddha dating back to the 12th century have been found in a secret cave system in a remote area of Nepal, according to a team of international researchers.

This photograph shows one of 55 panels depicting the story of Buddha's life found in a remote cave in Nepal.
(Sky Door Productions/Luigi Fieni/Associated Press)

The team of Nepalese, American and Italian archeologists, art experts and climbers said they found a mural with 55 panels portraying Buddha's life in March in Nepal's Mustang area, about 250 kilometres northwest of Kathmandu.

One of the largest panels is 7.6 metres wide while others measure 35 by 43 centimetres.

A nearby cave contained manuscripts written in Tibetan along with pre-Christian era pottery shards.

The panels and manuscripts were in a system of caves with multiple floors connected by vertical passages with rough hand and footholds, the team members said.

They had to use ice axes to break through the snow to reach the caves after being tipped off by a sheep herder.

"What we found is fantastically rich in culture and heritage," Broughton Coburn, a conservationist from Wyoming, told the Associated Press.

"Who lived in those caves? When were they there, when were [the caves] first excavated and how did the residents access them, perched as they are on vertical cliffs?

"It's a compelling, marvellous mystery."

The caves are located in an area that had been inaccessible for many years. The expedition spent three weeks in the region, often used as a route between Nepal and Tibet.

The team has decided to keep the locale hidden from the world out of fears that more visitors could lead to its ruin. They have only just come out with news of its discovery.

Coburn said the team plans to return and perform a limited excavation, collection and cataloguing of the manuscripts.

"We learned how much we don't know, how much there is to discover, explore and understand."

American Peter Athans, a world-renowned mountain climber who has repeatedly reached the summit of Mount Everest, was also a member of the team.

Athans said the discovery has capped his career.

"The opportunity to explore new ground with potentially significant discoveries … was far more enticing than the Everest summit."

With files from the Associated Press