A young man washed off rocks while fishing at a remote South Taranaki beach began swimming to shore before another wave pushed him under, a local councillor who lives at the beach says.
The man hasn't been seen since.
Brian Rook lives at Waiinu Beach, about 40km west of Whanganui, where a combined air, sea and land search - including by the man's devastated family - has been taking place since he disappeared this morning.
Rook said he had also seen light aircraft in the skies over the beach.
The South Taranaki district councillor didn't want to share the man's name, but said he was about 30 and from South Taranaki.
He'd been told the man initially resurfaced after being washed into the sea.
"Him and a mate were fishing at a spot called Snapper Rock. He got washed off the rock and was swimming back to the beach when another wave pushed him under.
"It's tragic."
After the alarm was raised about 11.30am, police search and rescue, Coastguard Wanganui and surf lifesavers, along with a helicopter crew, began looking for the man.
It wasn't known if the man was wearing a life jacket, a police spokeswoman said.
The official search had now been stood down for the day, she said just after 5.30pm.
"Teams will reassess tomorrow morning."
Family and friends of the man, along with Waiinu Beach residents, have also been searching the shoreline in four-wheel-drive vehicles since the man disappeared, Rook said.
"I imagine they'll be out there all night."
There were about 80 houses at Waiinu Beach, around 70 per cent of which were permanently-occupied.
He had lived there about 20 years and said Snapper Rock wasn't considered a "notorious place" for danger.
"The sea wasn't very rough today, and there wasn't any wind or rain. The sun was shining.
"It was a beautiful day to be fishing, especially off the rocks with a mate."