Extensive searches was still underway for a woman missing in a swollen Northland river this afternoon and will continue tomorrow if necessary, police said.
Search efforts were likely to be suspended as it got dark, a spokeswoman said.
The woman, believed to be visiting Haruru Falls from Wellington, was swept away while trying to return to a house from her partially submerged vehicle.
It's believe she had attended a party along with several others at the residence the night before. She was last spotted about 6am clinging to a tree.
When police arrived three other people were either stuck in trees or on top of cars and shed roofs.
Police had been working with the Fire Service and Westpac in what they described as "treacherous conditions" using helicopters, jet skis and IRBs to search the surrounding areas and assisting others who'd been stranded due to flooding.
Police said the area was extensively flooded and strong currents across paddocks lead into the Waitangi River.
Deployment manager Inspector Greg Dunn said flood waters were receding and searches would continue tomorrow if necessary.
Victim Support and police were liasing with the next of kin.
Earlier, a spokesman for the Northland police district command centre, which is organising the rescue effort, said it was difficult receiving details from rescuers on the ground.
"All I can say is we're still looking for her at this stage. It's a bit sketchy with the reception we're getting," he said.
"As you can appreciate we're pretty flat out with everything else - not only that, all of the flooding as well."
Fire Service north communications shift manager Paul Radden said the Fire Service had ceased their operations there.
Eyewitness Jordan Rivers said a group of people had been attending a farewell party at the rural property at the top of the falls, and then about 6am a 28-year-old woman tried to cross an area that had been flooded.
He spoke of their desperate attempt to rescue the woman before calling the rescue helicopter.
"We all tried to make human chains, we tried an extension lead, we tried to make a rope, we tried everything we could."
Three others had been swept away during the rescue attempt but had made it out, he said.
Police said they were searching by land, river, sea and air for the missing woman.
She was swept into a fence where she got caught and went underwater, Rivers said.
"She was holding on to the fence and went under". She had not been seen since.
Another witness, Damian Skeens, said he had also been in the water.
"I just got nearly killed," he said.
Other witnesses at the scene were not aware of anyone else missing, other than the woman.
Northland Search and Rescue called the Coastguard about 6.45 this morning requesting the use of their rescue vessel Bay Rescue.
The rescuers were making their way up to the mouth of the Waitangi River to conduct the search for the woman.
They were having difficulty getting under the Waitangi Bridge due to excess debris, the high tide and flood water.
Earlier rescuers were trying to get hold of enough inflatable dinghies to rescue three or four other people understood to be trapped in a tree.
Twin Pines Tourist Park manager Richard Harries said he had a view of the waters where the woman was swept away and had been called by the Fire Service about 8am and asked to keep out a look out.
"It's pretty turbulent and fast flowing down there," he said.
"Not nice at all."
Although the weather was good now, last night was a different story, he said.
"The nail in the coffin was all the rain. The two campgrounds next to us are flooded. The water does come up pretty high, I don't know if they were in a camper van or something.
"Its very still at the moment, no wind, no rain, it's just fairly cloudy."
Several other people had to be rescued this morning after their vehicles were caught in flood waters.
A welfare centre has been set up at the Haruru Bledisloe Hall for residents affected by flooding.
Northland Civil Defence Emergency Management Group spokesman Graeme MacDonald said the welfare centre was in the process of being set up to provide food and heating for any families immediately needing assistance.
Five families had to be evacuated from their homes.