The rescue team almost cracked emotionally when they found the climbers' belongings such as a toy penguin

Authorities on Monday showed heart-wrenching images of the final moments of an international team of climbers swept away in an avalanche as they attempted to scale an unconquered Himalayan peak.

The 154-second clip shows the four Britons, two Americans, an Australian and their Indian guide roped together in bright sunshine as they take nervous, synchronised steps along a narrow ridge towards a snow-capped peak.

Then the screen goes blank.

Last visuals of the mountaineers' team near the summit on unnamed peak near the #NandaDevi east. ITBP search team of mountaineers found the memory video device at 19K ft while they were searching the area where bodies were spotted. pic.twitter.com/0BI87MEA8Y — ITBP (@ITBP_official) 8 July 2019

"Suddenly we noticed a loud noise. The video went blank and stopped," said Vivek Kumar Pandey, spokesman for the Indo-Tibetan Border Police (ITBP).

"They were crossing a very dangerous ridge. The snow cornice must have given away because of their weight, triggering an avalanche," he told news agency AFP.

The camera, that was carried by the final climber in the line, was found buried in snow near where seven bodies were uncovered.

An eighth climber, British team leader Martin Moran, is still missing, according to authorities.

In addition to Martin Moran, the climbers were Britons John McLaren, Rupert Whewell and University of York lecturer Richard Payne, US nationals Anthony Sudekum and Ronald Beimel, Australian Ruth McCance and guide Chetan Pandey.

"It was mesmerising for us to see the footage," said APS Nambadia, the ITBP deputy inspector general who planned the operation to retrieve the bodies.

"It will help us to analyse what went wrong with their mission," he told a press briefing.

"The GoPro has proved to be like the black box of an aircraft giving an insight into the last few moments of the climbers."

"Put our lives at risk"

Mr Nambadia said the operation to find the bodies at an altitude of 6,100 metres had been "extremely challenging".

Twelve climbers had started the expedition, but four Britons were rescued after breaking away.

The missing climbers last communicated on May 26, a day before heavy snow fell in the region.

On June 3, a military helicopter spotted the bodies and climbing equipment in the snow but several attempts to airlift the bodies away were aborted due to fierce winds and the difficult terrain.

The ITBP then sent its expert climbers on foot to bring the bodies down.

SS Deswal, the ITBP director general, said the rescue team risked their own lives to retrieve the bodies "with respect and dignity".

"We put our own lives at risk and undertook the operation by foot. We slept with the dead bodies on the side for days," said Ratan Singh Sonal, an ITBP officer who led the rescue team.

"At night we would bury the bodies under snow outside our tents to slow down the decomposition process," Mr Sonal told AFP.

"But we were not afraid. We felt we are all a part of humanity."

Mr Nambadia said the exhausted rescue team almost cracked emotionally when they found the climbers' belongings such as a toy penguin.

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While retrieving the bodies, ITBP mountaineers were so emotional to see this Penguin doll at the site from where dead bodies retrieved in the #NandaDevi search mission. Some belongings of those mountaineers. pic.twitter.com/W5K69soNes — Vivek Kumar Pandey / विवेक कुमार पाण्डेय (@vivekitbp) 4 July 2019

"They were emotionally charged when they found the baby (toy) penguin. It was symbolic of the emotions of a mountaineer and my team could relate to it."