Shellfish collectors on Northland's west coast are being warned to know the difference between species, with five people facing prosecution for allegedly taking 214 toheroa.
An honorary fishery officer stopped the five people in a vehicle on Bayleys Beach about midday on Sunday and discovered the shellfish, which cannot be disturbed or removed unless people have a customary permit.
The shellfish were counted and photographed before they were returned to the sea.
The officer's report on the incident will be considered by Ministry of Primary Industry staff, who will decide whether afine should be issued.
People caught with, or having disturbed, fewer than 50 toheroa face a $500 instant infringement fine. If an incident involves more than 50, the accused will go to court and be prosecuted, facing a maximum fine of $20,000.