A family member has described the emotional moment a man and three children missing for almost three weeks "just walked in the door" at a remote North Island settlement today - safe and alive and in tears.

Police confirmed the man - Tom Phillips - and his three children had all been located in the South Waikato settlement of Marokopa since being reported missing almost three weeks ago.

Phillips and his three children - Jayda Jin, 8, Maverick, 6, and Ember, 5 - had not been seen since September 11. His ute was found on a nearby beach, facing out to sea.

Police and emergency services - as well as hundreds of locals and volunteers - spent days searching for the family in the area of Kiritehere and Marokopa since Monday, September 13.

Phillips' sister Rozzi Pethybridge told Newshub he "just walked in the door".

"As Dad said, 'I just hope he walks in,' and he has. This is the best-case scenario," said Pethybridge.

"I talked to him for about two minutes and there were lots of tears. I want to be respectful of Tom's wishes so I can't say too much at the moment, but Tom was in a helpless place - he chose a safe place to clear his head."

Tom's mother, Julia Phillips, told the Herald they were "just relieved and really thrilled" that they had returned home.

She said her daughter Rozzi was due to speak on behalf of family tomorrow but they were "absolutely thrilled" they had come home unscathed.

Police are due to release more details this afternoon.

Otorohanga Mayor Max Baxter said there was an "overwhelming sense of relief". He said he was really pleased the three children were safe and sound, but Tom did have a lot of questions to answer.

"There will be mixed emotions on behalf of the family, there's no question. As the communities will have the same mixed emotions. But at the end of the day there will be an overwhelming sense of relief that the kids are safe and sound."

And Baxter told RNZ it had been an extensive search and he commended police for following through on the missing family.

He said he didn't know where the father and children had been, but he was "of the understanding, it is well thought through prior to going bush" so there would be a few questions to be answered.

Waitomo Mayor John Robertson said he was "over the moon" when he was given a heads up by police early this morning that the family had been located safe and well.

"Huge relief and I guess a huge surprise they were found... it's just great, great news really when you think of the children."

Robertson said the children had been on the community's mind for the last three weeks.

"No one knew. We just could not fathom this one so the assumption was they might have been lost at sea."

'Our biggest fear is a rogue wave'

Earlier this month, the children's uncle, Paul Phillips, was getting more and more nervous about finding them alive.

"Our biggest fear is that it's possible that a rogue wave came in and swept them out to sea. Because Tom was an extremely resilient person we're hopeful that Tom has taken the children camping," he said at the time.

"That's something that he was more than capable of, yes, he was a very resilient man, a capable hunter and he knew how to look after himself and knew his way around the bush.

"It's looking more and more likely that it's not the answer we want," Phillips told the Herald last week.

We all just want them home - mother

The children's mother also earlier thanked those who had been involved in the search, including Waikato Police Search and Rescue staff, Waitomo LandSAR, Hamilton LandSAR, Fire and Emergency New Zealand,and Surf Life Saving NZ.

"We also want to thank the air support units who have been helping with the search, the local Iwi and community for their support, and preparation of food donations, any koha given and the families of everyone mentioned for supporting them during their time helping our family.

"We have been incredibly humbled by the generosity and support shown by everyone during this difficult time.

"We all just want Tom, Jayda, Maverick and Ember home."

Just less than a week ago, authorities announced that daily searches for the group would be suspended.

"The family understands police remain committed to bringing their loved ones home, however at this time the daily physical searches will be suspended and we will move into a 'reactive' phase," area commander Will Loughrin said at the time.

"This means police will be available to react to any new information as it comes to hand and initiate searching as required," he said.

Loughrin said at the time the inquiry phase of the operation was still ongoing with investigators continuing to follow-up information as it came in.

He asked anyone who found any items of interest, including clothing, on the coastline areas extending as far north as Papanui Point (near Raglan) and as far south as Waikawau Beach, to contact police.

It was initially thought the family may have been missing at sea after Phillips' vehicle was found at the beach.

The ute was parked facing the sea at Kiritehere beach the day after the family were last seen.

The keys had been put under the mat.

The circumstances of the family's disappearance and exactly how long they have been in Marokopa since being reported missing have not been revealed.

Loughrin said more information would be given at a press conference planned for 3pm today.