The sightseeing helicopter plunged into the Fox Glacier, a popular tourist site on the west coast of the South Island, with weather conditions reported to be heavily overcast and raining at the time.
A paramedic and alpine rescue team who looked over the crash site confirmed there were no survivors.
"A helicopter carrying seven people including the pilot has crashed at the top of the Fox Glacier," inspector John Canning said.
Canning said the recovery effort could take time because of the atrocious weather.
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"I'm not going to risk any more lives, we've lost seven," he said.
"The terrain at the top of the glacier is very rough, as you can imagine it's icy and there are crevasses -- it's quite dangerous."
Grey District Mayor Tony Kokshoorn described weather conditions around the glacier at the time of the accident as "terrible" with heavy rain and poor visibility.
A statement later posted to the police website said two Australians and four Britons were killed, while Canning confirmed the pilot was a local man. Their names have yet to be released.
"Police have been liaising with the embassies of the countries concerned to ensure the next of kin are advised of the situation," the statement said.
Debris from the wrecked helicopter was spread over several hundred metres with the main part of the aircraft wedged between house-sized blocks of ice.
The alarm was raised late Saturday morning when an emergency locator beacon was activated.
A spokesman for Alpine Adventures, which operated the single-engine Squirrel helicopter, confirmed it was on a scenic flight with six passengers.
New Zealand's Transport Accident Investigation Commission said it would investigate the cause of the crash and had sent four investigators to Fox Glacier.
Alpine Adventures advertises itself as an "experienced helicopter flight-seeing company providing visitors with a diverse range of South Island scenic helicopter flights and private charters in some of (the) most spectacular alpine and coastal regions of New Zealand".
Fox Glacier is 13 kilometres long and is listed as one of the most accessible glaciers in the world, attracting thousands of tourists each year.