AN avalanche on a New Zealand mountain killed two experienced climbers - but the third person in the group somehow survived.

Three people were buried under snow while climbing Mount Hicks in New Zealand’s South Island on Wednesday morning, police said.

Despite the swift efforts of rescue teams, two men who were the guides for the expedition, were found dead shortly after.

Jo Morgan survived an avalanche that buried her on New Zealand's Mt Hicks. She spoke to RNZ about the experience.
YouTube - RNZ

However, Kiwi adventurer Jo Morgan managed to dig herself out after 40 minutes and set off a locator beacon.

“I’m absolutely broken,” Ms Morgan told TVNZ later in the day, calling the dead men very dear friends.

“We weren't being foolish or anything and we just hit a slope ... laden with the type of snow that avalanches,” she said.

“We were tied together and I survived. They were buried and I was buried, but had my face out so I could breathe.”

Officials have praised Ms Morgan’s actions, describing it as a textbook recovery.

“She has done an amazing job extricating herself,” Department of Conservation director-general Lou Sanson told the NZ Herald.

"She had her (locator beacon) right close to her body which has undoubtedly saved her life.

Police have yet to name the two men and say their deaths will be referred to the coroner.

Their bodies have been recovered and next of kin notified.

Ms Morgan is the wife of well-known New Zealand millionaire and economist Gareth Morgan.

An experienced mountaineer, she is understood to have climbed 22 major peaks.

Her party departed at 2am on Wednesday hoping to take advantage of a window in rough weather.

Two helicopters, an eight-person rescue crew and a dog were involved in the search.

Mount Hicks is about 3200 metres high.