A Nepali guide abandoned his client's Everest summit bid to rescue a Malaysian climber in a deadly mountaineering season that has seen at least twelve deaths.

Gelje Sherpa was guiding a Chinese client to the 8,849-metre (29,032-feet) peak and planned to assist him to paraglide down.

The area above 8,000 metres has earned its name because of its thin air, freezing temperatures and low oxygen levels that heighten the risk of altitude sickness. It is also notorious for its difficult terrain.

"When I found him in that state, my heart did not let me leave him there," Sherpa told AFP.

Many other climbers had walked past the man that day, but he declined to criticise them.

"It is a place where you have to think of your survival first," he said.

Sherpa told his client -- who will have paid at least $45,000 to attempt Everest, including a permit fee of $11,000 -- to return without a summit.

The rocky uneven terrain meant that Sherpa, who is about 1.6 metres tall (five feet and three inches) and weighs 55 kilograms, had to carry the Malaysian in some sections.

"It is a very difficult task to carry someone and bring them down from there. But some sections are very rocky, I couldn't drag him," said Sherpa.

"If I did that, he could have broken his bones, he was already not doing well."

Sherpa hauled the man down nearly 700 metres for almost six hours to Camp 4 by himself.