The alert for toxic sea slugs found on the shores of Auckland's east coast beaches has now spread to the Manukau Harbour.
One of the slugs has been found on the harbour coastline, and the Auckland Regional Council is warning dog owners to ensure their animals don't eat them.
It says all Auckland beaches should now be considered suspect.
In August and September last year 15 dogs became unwell with symptoms of poisoning from the toxin TTX after eating sea slugs in the Hauraki Gulf.
Six of the dogs died.
RadioLIVE