Searchers are focusing on the Marokopa coastline in the mission to find Thomas Phillips and his three young children.
Thomas Phillips, 34, and his three young children, Jayda Jin, 8; Maverick Callum-Phillips, 6; and Ember Phillips, 5, were last seen by family at Marokopa on Saturday evening.
Sergeant Sean Keeley told media at Marokopa Town Hall that Land Search and Rescue teams have no found evidence they are in the bush.
He says they are focused on searching the coastline, which includes the nearby bush and sea.
It is not known what any of them were last wearing.
Police, with the approval of family, today released photographs of Phillips and his children.
"We want to acknowledge the family's incredible strength at this very difficult time and thank them for their on-going help," Waikato West Area Commander Inspector Will Loughrin said.
There is still no sign of the missing family after four days of intensive searching.
"We are in a remote, isolated area, communications are hard, the weather hasn't been favourable but it is a credit to everyone involved in the search that this hasn't held them back at all and they have continued on in some pretty harsh weather conditions," Loughrin said.
Sergeant Sean Keely, who is heading the search operation said the sea area covers a large portion of the King Country west coast from Tahāroa in the north to about 15 nautical miles south of Marokopa.
He describes a sea search as dynamic and forever changing.
"We do have to go over that all of the time because as the tides come in and out our scene changes. Also in terms of the size of the search area because it is dynamic our search area continues to expand."
He said land searchers have come up with nothing.
"We haven't found any clues in sign cutting or tracking that would indicate that Thomas and the children have been through the areas we have searched."
Loughrin said police are keeping an open mind about what has happened to Phillips and his children.
"We are exploring all viable scenarios."
He was asked are police not, then, ruling out foul play.
"At this stage, there is no indication of foul play."
Detectives are running an investigation parallel to the search working on the family's movements.
Loughrin describes it as wide-ranging.
"Bank inquiries, phone inquiries. We are speaking to family and friends, associates, anyone that knows Tom, the kids and the family. That allows us to build a really clear background and build up a profile of the family, which also informs our searching where possible locations could be."
Keely said not ever being able to find the family is a possibility, but not one being explored at this stage.
"We are optimistic, holding out hope like the family. We have put a lot of resources into (it) and we will continue to find Tom and the kids and you would have seen that from staff on the ground and helicopters, drones, planes. We have put everything into the search to find this family."
Loughrin said the search is being regularly re-assessed, but that they are not yet at the point where everywhere possible has been searched.
Police want to speak to anyone who was in the Marokopa or Kiritehehe Beach areas either Saturday or Sunday, September 11 and 12.
"While you might not think you have seen something, we want to hear from you.
"This includes bach owners or visitors who may have left the area after the weekend."
They ask people to contact the investigation team via 105 and quote file number 210913/1952.
Surf Life Saving New Zealand's Allan Mundy says there are currently 17 lifeguards on the water, including swimmers searching caves.
Surf lifesavers are using inflatable boats and a jetski in their search.
Mundy says the Rescue Co-ordination Centre is using the Galileo satellite system.
She said local knowledge on sea conditions is also a great help.
A childhood friend of Thomas Phillips has also joined the search for the family.
Murray Kawhena turned up at the search headquarters today wanting to lend a hand.
He describes his old friend as a quiet man with a big smile.
Kawhena says Phillips knew the sea conditions well and it would be a surprise if he had been swept out to sea.
He says members of the Ngāti Te Kanawa hapū are saying karakia that if that is the case Tangaroa returns him and his children to their families.