Paralytic shellfish toxins have been found in Waikato, prompting a warning against collecting or eating shellfish from the Kawhia region.

The warning affects Papanui Point, just south of Raglan down to Tirua Point, south of Marokopa and includes Kawhia and Aotea harbours.

New Zealand Food Safety says gathering or eating all shellfish could make people sick.

The full list of affected fish is: mussels, oysters, tuatua, pipi, toheroa, cockles and scallops, as well as pūpū (cat's eyes), Cook's turban and kina (sea urchin).

Cooking the shellfish does not remove the toxin.

Pāua, crab and crayfish can still be eaten if the gut has been completely removed before cooking, as toxins accumulate in the gut. If the gut is not removed its contents could contaminate the meat during the cooking process.

Paralytic shellfish toxins have been found in mussels from Kawhia wharf at levels over the safe limit of 0.8mg/kg set by New Zealand Food Safety.

The ministry's statement said symptoms typically appear between 10 minutes and 3 hours after ingestion and can include:

• numbness and a tingling (prickly feeling) around the mouth, face, and extremities (hands and feet)
• difficulty swallowing or breathing
• dizziness
• headache
• nausea
• vomiting
• diarrhoea
• paralysis and respiratory failure and in severe cases, death.

Earlier warnings remain in place for the collection of shellfish in the east coast of the North Island (from Cape Runaway south to Blackhead Point, just north of Pōrangahau) and Northland (Cape Karikari north to Kokota (the Sandspit), just south of Parengarenga Harbour).

-RNZ.