The family of one of the New Zealanders killed in an avalanche in Japan say she was full of vitality and passion for life.

Authorities had confirmed two New Zealanders were killed while skiing in Japan.

In a statement, the family of Isabella Bolton said she was among the dead.

"It is with a heavy heart that we confirm the passing of our beloved Isabella Bolton, 21, in an avalanche accident in Hokkaido, Japan on Monday, March 11."

They said Isabella was born in England but grew up in Diamond Harbour and Heathcote Valley.

She attended Christchurch's Rangi Ruru Girls High School.

Isabella had been working as a ski guide in Niseko since November, having previously worked on ski fields in Canada, Tekapo and Wanaka.

"Isabella was full of vitality and passion for life," her family says.

They say she had an "adventurous spirit and love for skiing and the outdoors".

"Our family would like to extend our deepest sympathy to the family and friends of her fellow colleague and friend whose life was also tragically lost.

"And to extend our gratitude to those who tried to save Isabella, and the local authorities."

They ask for privacy to mourn.

Authorities say the other New Zealander was a man in his 30s.

He and Isabella were part of a group of six backcountry skiing in Hokkaido when an avalanche hit.

The Japan Times reports the pair were taken to hospital and were later pronounced dead.

A third person, also a New Zealander, was injured.

The New Zealand Embassy has spoken to the person and has offered consular support as well as the families of those who died.

The Ministry of Foreign Affairs and Trade say following the avalanche, Japanese police had confirmed that two New Zealanders have died.

The avalanche hit three people in a group of six around 10am local time on Monday, the Japan Times reported.

It occurred at an elevation of about 650-700 metres on the northern slope of the 1900 metre high mountain, the report says.

Mt Yotei is in the Hokkaido region, which is a popular destination for skiers and snowboarders.

- RNZ