The Northland forest in which a helicopter crashed, killing two people, is so dense no wreckage was visible even from the air soon after the accident.
Emergency services could use only four-wheel-drive vehicles or walk to access from a forestry road in the Glenbervie Forest where a Robinson R44 chopper crashed just after 2pm yesterday.
The forest is owned by Rayonier and the two people who died were believed to have been surveying the forest, north of Whangarei, when its locator beacon was activated at Lookout Rd just after 1pm.
At 3.20pm, Rayonier staff at the company office locked the main gate leading to the forest after allowing two fire appliances from Whangarei and a Forest Protection Services crew through.
Police and fire crews set up a tent near the crash site, which is up on a hill amidst a mixture of pine and native trees.
Two fire trucks were parked about 5km down from the crash site and it's understood they were not required.
None of the chopper's remains could be seen from about 300m above the ground. It is believed to be a commercial helicopter.
Police said they were investigating what the chopper was doing before it crashed and were identifying the bodies of the people killed and contacting their next of kin last night.
They were believed to have been well-known in forestry circles in Whangarei.
Before emergency crews arrived, a Northland Rescue Helicopter winched a paramedic to the site but those on board the R44 were already dead.
The crash comes after the Transport Accident Investigation Commission (TAIC) added Robinson Helicopters to its list of safety concerns last week.
Peter Northcote, spokesman for TAIC, said the organisation could not confirm whether it would conduct an inquiry into yesterday's crash until it had more information about what had happened.
The Commission opens an inquiry when it believes the circumstance may have significant implications for transport safety or allow new findings or recommendations which may increase safety.
It would not speculate or comment on any potential relationship between yesterday's accident and its list of safety concerns regarding Robinson Helicopters.
They have been involved in 18 other deaths in New Zealand recently, and the model has been put under the highest possible level of scrutiny.
Civil Aviation Authority spokesman Mike Richards said all it knew was a report of a crash and was gathering more information late yesterday.
He said police would be the lead agency initially.
Louisa Patterson, who lost her 18-year-old son James Patterson-Gardner in a chopper crash last year, said last week the R44 model, which crashed yesterday, claimed 44 lives globally in the past 21 months.
"Nothing will bring back Steve and James, nor the other victims of the many inflight breakups of this aircraft type," she said on Thursday.
"Other Robinson accidents have been blamed on turbulence or pilot inexperience. In our case, the instructor was experienced and from the tracking data, the aircraft was being
flown in the cruise, in calm weather and at a safe altitude."
Out of respect for the victims' families, Ms Patterson declined to comment on yesterday's crash, except to say in a statement she offered her "full condolences" to the loved ones of those killed.
Robinson R44s have been plagued by so-called mast-bumping incidents, in which the main rotor blades strike the cabin, causing the helicopter to break up in mid-air.
Fourteen such incidents have been investigated since 1996.