A Sherpa climbing guide who was believed to have died high on Mount Everest says he survived by “chewing ice” and eating chocolates he found in his pocket.

Dawa Sherpa, also known as Hillary Dawa Sherpa after Edmund Hillary, was last seen on 29 May but did not arrive at base camp with other climbing groups.

Dawa was found crawling back to Base Camp after spending almost a week on the mountain with no food or bottled oxygen. He told rescuers he had been forced to stay behind after his oxygen ran out.

A clean-up team saw him “sliding” down the snowy slopes towards Base Camp.

Nepal Mount Everest, a hiking company that participated in the search, called his rescue “nothing short of a miracle” in a post on social media. “Dawa’s willpower is truly inspiring, he refused to give up!”

A fellow climber said he was last seen on May 29 resting above Camp 3, which sits at 7,060 metres. It is known as the “death zone”, because the pressure is so low that oxygen levels are insufficient for sustained human survival.

The 52-year-old was airlifted to hospital in Kathmandu, where he received treatment for dehydration, frostbite on his hands and a fractured bone.

“I didn’t think I would be alive,” he told the BBC. “I thought I would perish this way.”

Though Dawa had been missing since last week, there was a delay in organising a search team. No reasons were given for the delay, but when helicopters were finally sent to look for him, they could not find him.

His family had given up hope he would return. Dawa’s teenage daughter, Mendo Lhamu Sherpa, said they were on the second day of a funeral ritual, which lasts for several days.

“When we first heard about it [the rescue], we could not be sure if that person was indeed our father,” Mendo Lhamu said. “So to be certain we asked for photos to be sent and then only we were sure and very happy.”

Dawa works for a small Kathmandu-based company called Himalayan Traverse, and was guiding a Polish climber.

He became separated from his client and climbing team, who had already descended and were among the last group on Everest before it closed for the season.