Experts have new concern about Mount Everest after missing British climber is feared dead

A new concern has been raised following the tragic news that a British climber went missing during an expedition up Mount Everest.

Dan Peterson, 40, from Wakefield, UK, and Pastenji Sherpa, 23, who was his guide from Nepal, have not been seen or heard from since Tuesday 21 May.

They managed to reach the mountain's summit at 8,848m before 5am on Tuesday, they have not made any contact since.

Dan's partner, Becks Woodhead, has also asked 'urgently' for people's help and financial support.

She wrote on a GoFundMe page: "My name is Becks Woodhead and I am the partner of Dan 'Pat' Paterson. Dan's family and I, urgently need your help.

"Tragically, during his descent, Daniel went missing, and there has been no contact or sighting of him since. Time is of the essence in a situation like this, and we are mobilising every resource we can to locate Dan."

"Conducting a search and rescue operation on Everest is an incredibly complex and costly endeavour. We are not experts in this, and there is no guarantee of success," she concluded.

The disappearance of Paterson and Sherpa also coincides with a landslide of snow and ice on the mountain, as it believed that a cornice - known as an overhang of hardened snow - may have collapsed.

However, a new concern has been raised following a post on social media showing hundreds of climbers making their way up Hillary Step, an almost vertical rock face near the peak of Everest, at about 26,000 feet (7925m).

Experts fear that the massively overcrowded queues on the rock's face may have played a part in the collapse of a cornice.

According to Everest Guide and founder of 8K Expeditions, Lapka Sherpa, the Brit, and his guide, who'd both used his company, said they had searched for the pair after they'd reached Everest's peak.

As reported by Sky News, he said: "Despite exhaustive search efforts, we regret to confirm that Daniel and Pastenji were unable to be recovered."

Everest guide Vinayak Malla, who is as a member of the International Federation of Mountain Guides Associations (IFMGA), also commented on the case of the missing pair.

She was climbing Everest on that fateful Tuesday, sharing on Instagram that reaching the summit 'felt different' to her previous climbs.

Malla posted: "After summiting, we crossed the Hillary Step, traffic was moving slowly then suddenly a cornice collapsed a few metres ahead of us. There was also a cornice under us.

"As the cornice collapsed, four climbers nearly perished yet were clipped onto the rope and self-rescued.

"Sadly, two climbers are still missing. We tried to traverse yet it was impossible due to the traffic on the fixed line," she concluded.

According to Outside, at least 12 people died climbing Everest last year - with overcrowding often blamed for the number of deaths.

You can donate to help find Dan and Pastenji here.