Shellfish along much of the North Island's west coast could cause numbness, dizziness or respiratory failure if eaten, health officials warn.

Shellfish from Mohakatino in Taranaki north to Kaipara Heads have returned high levels of paralytic shellfish poisoning during routine shellfish toxin testing.

It has prompted the Auckland Regional Public Health Service to today issue a public health warning against eating any shellfish in the area.

The shellfish affected are kina, mussels, toheoa, pipis, tuatua, oysters, cockles and scallops.

Cooking shellfish does not remove the toxin.

Symptoms of paralytic shellfish poisoning usually occurred within 12 hours after eating shellfish containing the toxins.

Symptoms include:

* Numbness and tingling around the mouth, face or extremities

* Difficulties in swallowing or breathing

* Dizziness, double vision

* In severe cases, paralysis and respiratory failure.

- APNZ