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.

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.