Beachgoers are warned not to touch dead poisonous porcupine fish that have washed up on several beaches on the North Island's east coast and as far north as Auckland.
The fish, commonly known as pufferfish or blowfish, were washed ashore all over Waihi Beach at Labour weekend, local veterinarian Beach Vets said.
Bay of Plenty Regional Council coastal scientist Josie Crawshaw said they were aware of many pufferfish washing ashore at Waihi Beach and possibly other beaches in the region.
"This sometimes happens during stormy weather," Dr Crenshaw said. "We advise people and pets to keep a safe distance and not touch the fish as they have a neurotoxin in their skin and intestines."
In Coromandel, sightings of the fish have been reported at Whangamatā, a Thames-Coromandel District Council spokesman said.
There have also been sightings of the fish on Auckland's Snells Beach, according to photos posted on social media, although the council wasn't aware of this sighting or any others in the region.
Pufferfish contain an extremely potent neurotoxin called tetrodotoxin (TTX), which can cause muscle paralysis and an inability to breathe if ingested.
Ministry for Primary Industries (MPI) fish compliance regional manager Adam Plumstead said the beaching hadn't been reported to them - but urged beachgoers to be cautious.
"These fish are considered poisonous and our advice is not to handle them," he said in a statement.
Anyone needing further advice should contact the local council, he said.
Beach Vets also urged people to be watchful.
"These guys can be fatal if even licked," a post on the vet's Facebook page said. "We have removed as many as we can but if you see one please bury or remove.
"If you or your dog licks one call vet or medical centre immediately."
Initial symptoms following tetrodotoxin (TTX) poisoning can include numbness around the mouth, tingling, pricking of the skin and nausea. In severe cases, paralysis rapidly advances with respiratory problems first appearing as difficult or laboured breathing.