A shellfish public health warning has been lifted in all areas of the Auckland region.
The Auckland Regional Public Health Service made the announcement after receiving information that paralytic shellfish poisoning (PSP) levels have fallen to "non-detectable levels".
The Ministry of Primary Industries and Northland DHB said recent monitoring results from the Kaipara Harbour have shown that shellfish collection and consumption is now safe for the public across the entire Auckland region.
However, the PSP warning still remains in place for the Bay of Plenty.
"Levels of toxin found in shellfish are still high and there have been two further cases of illness reported over the Christmas and New Year holiday," said Dr Jim Miller, medical officer of health for Toi Te Ora - Public Health Service.
Twenty nine people have been poisoned by eating toxic shellfish in the area since mid-December.
"Paralytic shellfish poisoning can be a very serious illness, it can even be fatal," warned Miller.
"People have been really sick after eating shellfish from the Bay of Plenty, with some requiring treatment in the intensive care unit.
"Please look out for the signs and don't collect or eat shellfish from the affected areas."
Authorities have strongly advised against collecting shellfish from Tairua on the east coast of the Coromandel Peninsula, south to Waihi Beach and along the Bay of Plenty coast to Whakatane Heads in the Eastern Bay of Plenty. The warning includes Tairua Harbour as well as Tauranga Harbour, Maketu and Waihi estuaries, Matakana and Motiti Islands, and all other islands along this coastline.
The health warning applies to all bi-valve shellfish including mussels, pipi, tuatua, cockles, oysters, scallops as well as cat's eyes, snails and kina (sea urchin).
Eating shellfish infected with the poison can cause numbness and tingling around the mouth, face, hands and feet, difficulty swallowing or breathing, dizziness, double vision, and in severe cases, paralysis and respiratory failure.
Symptoms can start in as little as one to two hours after consuming a toxic shellfish, and anyone who experiences such signs is advised to seek urgent medical attention.