A woman and four children are missing after being last seen Te Urewera yesterday.
The five people were reported overdue from a bush walk just before 4pm.
The age of the children ranges from four to nine.
They had been dropped off just after one o'clock yesterday for a one to two hour walk.
Search and rescue teams and a helicopter have been searching in the Otamatuna Ridge area overnight and continue today. Te Urewera is part managed by a Tuhoe iwi authority Te Uru Taumatua.
Operations development manager Glenn Mitchell told One News the family is from Waimana. While he wouldn't disclose names he said that where the group was dropped off is near the Waimana Lions lodge.
"I do know the lady, I do know the experience," Mr Mitchell said.
"There's a short day walk, their intention was to do that walk but unfortunately it appears they set off on the wrong track.
"It's a point which is intensively managed for pest control with track lines for predator traps."
It wouldn't be difficult for an inexperienced person to wander off a marked walking track because of those lines, he said.
Mr Mitchell said the authority was pulling in its staff to make them available for the walk. He wouldn't comment on the level of concern but said overnight the weather had been fine with no local frosts.