A father who had been on the run with his three children in New Zealand's wilderness for nearly four years has been shot dead by police.

Tom Phillips, who disappeared with his children in late 2021, had evaded capture despite a nationwide search and multiple sightings over the years.

The case had gripped the country and remains one of New Zealand's most enduring mysteries.

Phillips was killed in a shoot-out around 02:30 (14:30 GMT Sunday) on Monday, in which a police officer was seriously injured, authorities said.

Officers were responding to a reported robbery at a commercial property in Piopio, a small town in northern New Zealand, when Phillips and one of his children were spotted riding a quad bike.

Police officers then gave chase before laying road spikes to stop them. The bike hit the spikes and went off road.

When police reached the vehicle they were met with gunfire, Deputy Police Commissioner Jill Rogers told reporters.

The first attending officer at the scene was shot in the head, and remains in a serious condition, police said.

A second patrol unit then engaged Phillips, who was shot and died at the scene. While the body had not been formally identified at the time of the announcement, police were confident it was Phillips.

The other two children were found later in the day at a remote campsite in dense bush. All three children are unharmed, Rogers said.

The child he was with, who has not been identified, had provided "crucial" information that helped them locate Phillips' two other children later in the day.

It was unclear whether the children had been informed of their father's death.

Police have notified their mother and Phillips' parents that the children are safe, though they declined to comment on who will provide ongoing care.

The children's mother, known only as Cat, told local media outlet RNZ she was "deeply relieved" that "this ordeal has come to an end" after missing her children dearly "every day for nearly four years." But, she continued: "We are saddened by how events unfolded today."

Authorities said Phillips had been evading capture since failing to appear in court in 2022.

Before they disappeared, Phillips and his children were living in Marokopa, a small rural town in the region of Waikato. Phillips, believed to be in his late-30s this year, had been described as an experienced hunter and bushman.

Police believe he took his children after losing legal custody of them.

Marokopa is an area surrounded by a very harsh landscape, a sweeping and rough coastline, dense bush and forested terrain with a network of caves spaning many kilometres.

Locals know Phillips as a bushman with survival skills that would have set him up for building shelters and foraging for food in the wilderness.

Still, there were signs that he got desperate for resources. Since 2023, there have been sightings of Phillips and his children at numerous break-ins at hardware and grocery stores.

Last October, a group of teenagers spotted them trekking through the bush and filmed the encounter. In the video, Phillips and the children were wearing camouflaged clothing and each was carrying their own packs.

The teenagers had briefly spoken to one of the children, asking if anyone knew they were there. The child had replied "only you" and kept walking, New Zealand's 1News reported.

Last year, a warrant was issued for the arrest of Phillips over his suspected involvement in a bank robbery in Te Kuiti, a small town on the North Island.

Police said he had had an accomplice during the alleged incident.

In fact, over the years, many have wondered if Phillips got any help from the tight-knit community in Marokopa, a town where fewer than 100 people lived, and the question remains unanswered.

Phillips's death comes less than a month after his family directly appealed to him to come home.

In an interview with local news website Stuff, his sister Rozzi said the family had been "ready to help [Phillips] walk through what you need to walk through".

"I really want to see you and the kids and be part of your lives again," she said then.

New Zealand's Prime Minister Chris Luxon has described the turn of events as "sad and absolutely tragic".

"This is not what anybody wanted to happen today. I think that is a consistent feeling from everybody across New Zealand," he said in a weekly briefing on Monday.

Other New Zealanders are also concerned about how Phillips's death would affect his children's wellbeing.

Marlene McIsaac, a resident in the Waitomo district, says she wished there had been "a happier ending". "For the kids, you know? The kids will be devastated," she told 1News.