Weather continues to hold up the recovery of the remaining bodies on Fox Glacier after a tourism helicopter crash on Saturday.
Plans are in place to head to the site on Wednesday when the weather is expected to clear. Police say a staging area will be stabilised on the glacier to provide a safe site for the rescue operation.
Two Australians, four Britons and a Kiwi pilot died in the crash at the popular South Island tourist spot on Saturday morning.
Police recovered four bodies yesterday by winching them out with a helicopter during a patch of clear weather.
South Westland Alpine Cliff Rescue team leader Marius Bron says the site is very unstable with ice cliffs and crevasses up to 20 metres deep.
Mr Bron likened it to a "giant bowl of popcorn," as the ice is stacked up with lots of gaps in-between.
West Coast area commander Inspector John Canning says the safety of the rescue teams is paramount, and will not be compromised in the recovery effort.
"We are waiting for a substantial break in the weather to get back on the glacier and systematically work through what is a highly technical recovery operation," he says.
Rescuers have to be on a winch or rope at all times.
The Transport Accident Investigation Commission (TAIC) has now begun formal interviews of witnesses and company pilots, though neither police nor the commission will comment on the possible cause of the crash.
A drone is being positioned to survey the crash site.
"We are a long, long way from identifying the circumstances and causes of the accident," says TAIC spokesperson Peter Northcote.
He says there was no mayday call from the pilot at the time of the incident.
Police are in close contact with the families of the deceased.