AFP/Wellington

The last remaining bodies from a New Zealand helicopter crash that claimed seven lives were airlifted from a glacier on Thursday after rescue crews took advantage of a break in the weather.

The sightseeing chopper, piloted by a New Zealander with four British and two Australian tourists on board, plunged into Fox Glacier on Saturday, but dismal conditions had stalled recovery efforts at the popular South Island tourist site.

Specialist alpine rescuers brought out four bodies on Sunday but had been frustrated in their efforts to reach the other three.

Police inspector Iain McKenzie said they were determined to make the most of improved conditions on Thursday.

"Within five minutes of sunrise we had our first teams landing on the glacier and work commenced immediately," he told reporters.

Police had originally said three bodies, not four, were recovered on Sunday.

Alpine rescue team leader Marius Bron said the heavily-crevassed glacier presented a major challenge for his team.

"It's really unstable, it's moving, the glacier's creaking and groaning, it's steep and slippery, so you're just on high alert all the time," he said.

Police sergeant Sean Judd said he was relieved the grim task of body recovery was over.

"It's a mixed feeling, given the job that we're up there doing," he said.

"But it is good to finally get that done. There was a lot of pressure on all of us this week and of course the families are the ones we feel for the most."

The helicopter wreckage was also brought down from the glacier as investigators attempt to piece together what went wrong, a task they have warned could take 18 months.

The helicopter did not send a mayday and police were only alerted when its emergency locator beacon was activated late Saturday morning.

The dead have been identified as Britons Andrew Virco, 50, and Katharine Walker, 51, of Cambridge; Nigel Edwin Charlton, 66, and Cynthia Charlton, 70, of Hampshire; Australians Sovannmony Leang, 27, and Josephine Gibson, 29, from Sydney; along with New Zealand pilot Mitchell Paul Gameren, 28.

The 13-kilometre-long Fox Glacier is listed as one of the world's most accessible glaciers and attracts thousands of tourists each year.