Pilot Nick Wallis has reportedly died in a helicopter crash near Wanaka - just three months after his brother died in similar circumstances.
Two male Department of Conservation (DoC) staff were also killed when the flight crashed shortly before 11am on Stevenson Rd near Wanaka Airport.
There are no survivors from the crash.
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The helicopter was on its way to Haast to begin the tahr cull.
A Newshub team was waiting for a helicopter to arrive at Haast for the start of the tahr cull, but it never arrived.
Warbirds Over Wanaka Community Trust Chair John Gilks told Newshub the pilot who died was Nick Wallis, the brother of deceased pilot Matt Wallis, who was killed in a helicopter crash in Lake Wanaka in July.
The 39-year-old's body was pulled from the wreckage of the crash, two days after an extensive search and rescue operation.
"We're facing the tragic death of Nick. It was only three months ago a similar accident took Matt's life," Mr Gilks told Newshub.
"It's an absolute tragedy for Nick's wife, his children and the whole of the Wallis family.
"The Wallis family have contributed so much over a long period of years to this community. It's a small community [and an] extremely high-profile, respected family - for this to happen, the whole community will be devastated."
Police confirmed the victim's families have been notified.
DoC Director General Lou Sanson is on his way to Wanaka and says he knew all the victims.
"This is a tragedy for our staff who are like family and are passionate about the work they do."
DoC's focus is to support the families and staff as they go through this emotionally taxing time.
TAIC has opened an inquiry into Thursday's crash.
The Chief Investigator of Accidents, Captain Tim Burfoot, says the accident involved a Hughes 500 helicopter.
"We are in the early stages of gathering information about the aircraft, the circumstances and the people on board," Capt. Burfoot says.
TAIC are sending a four-person investigation team to the scene.
Prime Minister Jacinda Ardern extended her condolences to the victim's families.
"DoC staff go out every day working on our behalf on our environment, sometimes in really dangerous situations and this is an absolute tragedy," she says.
Nick and Matt are the sons of aviation pioneer Sir Tim Wallis, WarBirds Over Wanaka founder and his wife Lady Prue Wallis.