An investigation has been launched into the death of a Pakistani porter near the peak of the world’s most treacherous mountain, a Pakistani mountaineer said, following allegations dozens of climbers eager to reach the summit had walked past the man after he was gravely injured in a fall.

The accusations surrounding events on July 27 on K2, the world’s second-highest peak, overshadowed a record established by Norwegian climber Kristin Harila and her Sherpa guide Tenjin. By climbing K2 that day, they became the world’s fastest climbers, scaling the world’s 14 highest mountains in 92 days.

Harila rejected any responsibility for the death of the porter, Mohammed Hassan, a 27-year-old father of three who slipped and fell off a narrow trail in a particularly dangerous area of K2 known as the ‘bottleneck’. In an Instagram post, she wrote that she felt “angry at how many people have been blaming others for this tragic death” and said no one was at fault.

Mohammad Hassan died on K2 after falling off a sheer edge at the top of the area known as the 'bottleneck', which is around 8200 metres high. Photo / Adventure Alpine Guides

Harila was defending herself against allegations from two other climbers who were on K2 that day, Austrian Wilhelm Steindl and German Philip Flaemig. The pair had aborted their climb because of difficult weather conditions, but said they reconstructed the events later by reviewing drone footage.

The footage showed dozens of climbers passing a gravely injured Hassan instead of coming to his rescue, Steindl told the Associated Press on Saturday. He alleged that the porter could have been saved if the other climbers, including Harila and her team, had given up attempts to reach the summit.

Steindl added that the footage shows “a man trying to rub [Hassan’s] chest, trying to keep him warm, to keep him alive somehow. You can see that the man is desperate.”

“We know by now that this was his friend, also a Pakistani high-altitude porter,” Steindl told the AP. “And what you also see in the drone footage is a line of 70 climbers marching towards the summit.”

“There is a double standard here. If I or any other Westerner had been lying there, everything would have been done to save them,” Steindl said. “Everyone would have had to turn back to bring the injured person back down to the valley.”

Steindl also said July 27 was the only day in this season on which conditions were good enough for mountaineers to reach the summit of K2, which explains why there were so many climbers so eager to get to the top.

Footage shows climbers clambering past the injured Pakistani porter Mohammed Hassan on a treacherous ridge on K2 on the same day Norway’s Kristin Harila ascended the mountain. Photo / 8K Expeditions

“I don’t want to kind of directly blame anybody,” Steindl said. “I’m just saying there was no rescue operation initiated, and that’s really very, very tragic, because that’s actually the most normal thing one would do in a situation like that.”

Harila told Sky News Hassan had been dangling from a rope, head-down, after his fall at the bottleneck, which she described as “probably the most dangerous part of K2″. She said after about an hour, her team was able to pull him back on to the trail.

At some point, she and another person from her team decided to continue to the top while another team member stayed with Hassan, giving him warm water and oxygen from his own mask, the climber said.

Harila said she decided to continue moving toward the summit because her forward-fixing team also ran into difficulties which she did not further detail in the interview.

Asked about Hassan’s gear, Harila said he did not wear a down suit and he didn’t have gloves, nor did he have oxygen. “We didn’t see any sign of either a mask or oxygen tank,” she said.

Meanwhile, an investigation has been launched into Hassan’s death, said Karrar Haidri, the secretary of the Pakistan Alpine Club, a sports organisation that also serves as the governing body for mountaineering in Pakistan. The investigation is being conducted by officials in the Gilgit-Baltistan region, which has jurisdiction over K2, said Haidri.

Norwegian mountaineer Kristin Harila and Nepali mountaineer Tenjen Lama Sherpa arrive at the airport in Kathmandu, Nepal, after setting a new record by climbing all 14 peaks above 8000 metres in 92 days and becoming the world's fastest climber. Photo / Getty Images

Anwar Syed, the head of Lela Peak Expedition, the company that Hassan was working for, said he died about 150 metres (490 feet) below the summit. He said several people tried to help, providing oxygen and warmth, but to no avail.

Syed said that because of the bottleneck’s dangerous conditions, it would not be possible to retrieve Hassan’s body and hand it to the family. He said his company had given money to Hassan’s family and would continue to help, but did not elaborate.

Asked about Hassan’s apparent lack of equipment, Syed said the expedition company pays money to porters to buy gear, and Hassan was paid the agreed-upon amount.

Steindl’s fellow climber, Flaemig, alleged in an interview with the Austrian newspaper Der Standard Hassan had no high-altitude experience. “He wasn’t equipped properly. He did not have experience. He was a base camp porter, and for the first time was picked to be a high-altitude porter. He wasn’t qualified for this,” he said.

Steindl visited Hassan’s family and set up a crowd-funding campaign. After three days, donations had reached more than €114,000 ($208,931) on Saturday.

“I saw the suffering of the family,” Steindl told the AP. “The widow told me that her husband did all this so that his children would have a chance in life, so that they could go to school.”