AFP/ Wellington

Six tourists and their pilot were killed when their helicopter crashed into a heavily crevassed glacier in New Zealand during bad weather on Saturday, police said.

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.

"We have been to the site and there is no sign of life and tomorrow we hope to recover the bodies of those involved."

Canning said the recovery effort could take time because of the atrocious weather.

"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.

"It wouldn't be a good day to be flying helicopters," he said.

The names and nationalities of the pilot and six passengers would not be released until their families were informed of the tragedy, however Canning confirmed the pilot was a local man.

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.

The New Zealand Rescue Co-Ordination Centre sent four helicopters to the glacier where they found a deep scorch mark leading to the helicopter about 2,500 feet (762-metres) up the glacier.

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".

Five years ago, nine people including four tourists were killed when a plane carrying a party of skydivers crashed on take off at Fox Glacier airport.

Fox Glacier is 13 kilometres (eight miles) long and is listed as one of the most accessible glaciers in the world, attracting thousands of tourists each year.