The Ministry for Primary Industries (MPI) has issued a public health warning advising the public not to collect or consume shellfish harvested between the Mohaka River mouth and Cape Kidnappers.
Routine tests on shellfish samples taken from the region show levels of Paralytic Shellfish Poisoning (PSP) toxins above the safe limit of 0.8mg/kg set by the Ministry.
"Anyone eating shellfish from this area is potentially at risk of illness," the warning states.
Mussels, oysters, tuatua, pipi, toheroa, cockles, scallops, catseyes, kina and all other bivalve shellfish should not be eaten, and cooking shellfish does not remove the toxin.
Paua, crab and crayfish may still be eaten if the gut has been completely removed before cooking, as toxins accumulate in the gut.