Thirty years after he perished in a small limestone cave near the top of Mount Everest, the body of the climber known only as “Green Boots” may finally be heading home.

If successful, the mission into Everest’s notorious “death zone” will also lay to rest any doubts about the identity of Green Boots.

Since 1996, it was often reported – but never confirmed – that the climber was Tsewang Paljor, an Indian climber killed on Everest during a severe blizzard.

But now that has been called into question. Indian authorities recently released a plan to retrieve Green Boots that contains information about the identity of climber – and also sets up an incredibly difficult recovery process.

The plan identifies Green Boots as Dorje Morup – not Paljor. Both Indian climbers died near the summit on the same day.

“That’s kind of a mystery to me, why all of a sudden the identity has changed,” says Alan Arnette, US mountaineer and prominent Everest blogger. “I’m glad that they’re bringing him down [but] it’s going to be a gruesome task.”

For decades, Green Boots has been stitched into Everest lore.

Named after his lime-coloured Koflach boots, Green Boots became a landmark for climbers tackling the tricky north-east ridge route, accessed from the Tibet and China side of the world’s tallest mountain.

Curled up as if napping, Green Boots is fully clothed and lies nestled under a small rocky alcove about 8,500 metres above sea level and just 350 metres from the summit. A red fleece is pulled up over his face; perhaps a final act as he succumbed to -30C temperatures and hurricane-force winds in a storm that was documented in Jon Krakauer’s bestselling book Into Thin Air.

Since 1996, climbers have used Green Boots as a macabre marker of their progress and timing up Everest’s 8,848 metres. Many radio back to base camp, informing support teams they have reached Green Boots. Others rest or seek shelter alongside the body.

In 2006, on his first summit from the north side, Tshiring Jangbu Sherpa encountered Green Boots as he sought shelter from strong winds under the rocky outcrop. A light dusting of snow had mostly covered Green Boots, he tells the Guardian. “When I touch[ed] him, I clear[ed] the snow a little bit. Then I totally saw Green Boots lying down under that snow.”

About 200 bodies remain on Everest. Grieving families make hopeful inquiries, but taking dead climbers down is often too hard or expensive, and helicopters cannot safely fly at such extreme altitudes.

Use the slider below to show a picture of the body of the climber known as Green Boots where it lies on Mount Everest. Some readers may find the image distressing:

A gruelling task

India’s plan to bring Green Boots home is contained in a tender document, seen by the Guardian, asking companies to bid for the mission. The specialist team must have at least six Sherpas who have summited Everest multiple times. They must provide evidence of the mission, and transport the body to Delhi by October.

The document explicitly names Morup as the climber called Green Boots. The identification of Morup “has been confirmed through a prior verification process conducted under an earlier tender/technical assessment”, the document states, without providing further detail. The tender does not state why authorities want Green Boots brought down.

In 1996, Morup and Paljor were part of an Indo-Tibetan Border Police (ITBP) expedition attempting a historic first Indian ascent of Everest from the north side. Both men pushed for the summit on the same day, along with a third member of the team. None made it down.

Tshiring Jangbu, the founder of Everest Sherpa Expedition, has been involved in numerous body recovery efforts. He says retrieving Green Boots will be arduous and dangerous, even for an experienced Sherpa team. With only a third of the oxygen available at sea level, activity above 8,000 metres requires huge effort and decision-making can become more difficult.

An iced-up body in climbing gear can weigh up to 200kg, Tshiring Jangbu says. And limbs frozen solid at awkward angles make dragging or lowering the corpse down rocky and icy terrain exhausting and treacherous work. Sometimes, he concedes, they must amputate a limb that “we cannot bend” – a gut-wrenching act, “but there is no choice to do another way”.

Such work takes a toll on the Sherpa, who are predominantly Buddhist, Arnette says. “They don’t believe in desecrating bodies, they really don’t even believe in touching bodies.” He believes a team would seek about $150,000 to carry out the expedition.

Nepal-based Makalu Adventure says monsoon weather conditions, with its heavier snowfall, will complicate a recovery between June and October, the timeframe stipulated in the tender. It estimates the mission, from start to finish, could take 40 days.

Guy Cotter is a New Zealand climber whose company Adventure Consultants operates expeditions in the Himalayas. In 1997, Cotter coordinated the retrieval from Everest of a climber who died the same year as Morup and Paljor.

“It would have been a good thing to have done a long time before now,” says Cotter, of the attempt to bring down Green Boots.

“For families to have a body returned from the mountain brings closure, as long as it’s not putting other people at undue risk,” Cotter says. “There have been situations with body recoveries where more people have died. It’s a very thin line.”

A family wanting the body can complicate matters, Arnette says, because many experienced climbers wish to be left on the mountain if they die on a climb, but to be moved out of sight.

In the past 10 years unconfirmed rumours suggest the body of Green Boots has been moved or buried. But Arnette says he has heard from climbers who insist Green Boots remains in the cave, “right where he’s always been”.