Shellfish along much of the North Island east coast continue to test positive for paralytic shellfish poison.
A health warning has been in place since 24 December when the toxin first emerged.
The affected area includes the Coromandel and Bay of Plenty coastline from Tairua in the north to the mouth of the Motu River in the eastern Bay of Plenty. It also includes all inshore islands in the affected area.
Medical Officer of Health for Toi Te Ora Public Health, Phil Shoemack, says shellfish sampling on Wednesday showed high levels of toxin.
Dr Shoemack says people should avoid all shellfish in the area until further notice.
The toxin can cause numbness and skin tingling, difficulty swallowing or breathing, dizziness, double vision and, in severe cases, paralysis and respiratory failure.