Nepal says Everest climbers 'must collect 8kg litter'
All mountaineers and support staff climbing Mount Everest must bring back at least 8kg (17lb) of rubbish each on their descent, Nepal's government says.
The new rules will come into effect in the spring and apply to those who climb above the Everest base camp at 5,300m (17,388ft), an official told the BBC.
It follows widespread concern over rubbish on and around the world's highest mountain.
Everest is particularly crowded in the climbing season, which starts in April.
The government already requires climbers to return all their rubbish or risk losing a $4,000 (£2,600) deposit.
But officials have tightened the rules now with the requirement that all climbers - and not just groups of climbers - must bring back 8kg of litter, not including oxygen cylinders and human waste.
"Once they submit the rubbish to officials of the Sagarmatha Pollution Control Committee on their return to the Everest base camp, they will get a receipt. They will need to submit that to us so that they can reclaim their deposits," Madhusudan Burlakoti told BBC Nepali's Surendra Phuyal in Kathmandu.
Many Nepali and foreign climbers have tried to clean up the mountain in the past.
In 2010 a team of Nepalese Sherpas made a journey to the highest reaches to clean up rubbish and retrieve the bodies of two climbers who died on the slopes.
Officials cannot say how much rubbish there is on the slopes of Mount Everest. Climbers say the higher they go, the more littered the mountain.