The names of seven people who perished when a helicopter plunged into a glacier in New Zealand have been released.

New Zealand police have identified the two Australians on board as Sovannmony Leang, 27, and Josephine Gibson, 29.

Police said the pair were residents of NSW. A family member said they both lived in Sydney and had known each other for some time.

Four British tourists - Andrew Virco, 50, Katharine Walker, 51, Nigel Charlton, 66, and Cynthia Charlton, 70 - are also thought to have been on the flight.

Pilot Mitch Gameren, 28, from Queenstown in New Zealand was also killed.

The helicopter crashed on the Fox Glacier on the west coast of South Island on Saturday. A paramedic and rescuer were winched down to to the crash site and found no one alive.

Poor weather conditions have hampered the effort to recover their bodies, with the helicopter stuck in a crevasse nearly 800 metres up the valley.

Recovery teams reached the site of the crash on Sunday, but West Coast Inspector John Canning said it could take days to retrieve the bodies.

Mr Canning said that crews would take "every opportunity" in intermittent breaks in the bad weather.

"We've got to get those [bodies] back to their families if we can." he said. "Definitely the people will be coming before the aircraft."

Mr Canning said crews would be not heading to the site by foot as it would take several hours due to the tough terrain and the difficult weather.

Foreign Affairs Minister Julie Bishop said that she had spoken to the families of the two Australians believed to have been on board.

"My sympathies are with the families of the crash victims at this very distressing time," Ms Bishop said.

"My department will remain in close contact with the New Zealand authorities as they respond to the crash and we will provide support to any affected families."

The scenic helicopter flight was operated by Alpine Adventures, which runs the Fox Glacier and Franz Josef Heliservices fleet.

Ground crew manager Mike Nolan described the crash as an "absolute tragedy".

"We just can't believe what's going on. We're just feeling for the families at the moment," Mr Nolan said.

"We don't know a lot about the recovery process just that the weather is hampering search and rescue teams. Mitch was one of our experienced pilots. We're devastated for him and his family. "

Mr Gameran, he said, had worked at the company for about six years and was as a "very valued member" of the team.

The young pilot's sister, Brooke, posted an emotional tribute to him on Facebook.

"Today we lost a champion. I lost my brother and best mate. I feel like I am in a dream and I'm just waiting for you to text me and tell me you're fine," she posted.

"I am so blessed to have a brother like you.

"You have been such a massive role model in my life ... I miss you so much already.

"There's so much more I could say but I can't think straight right now ... I love you so much big bro. Rest easy."

- with stuff.co.nz