Five fishermen were caught with 99 snapper, including 38 undersize fish in east Auckland on Saturday night.
Ministry for Primary Industries Auckland fishery officers seized a recreational boat after the group were found at the Half Moon Bay boat ramp in east Auckland.
As the daily bag limit for snapper in the Hauraki Gulf is seven per person, there should have only been 35 fish caught. The minimum size for snapper caught in the upper North Island is 30cm.
Fisheries Regional Compliance Manager, Andre Espinoza said investigations are still undergoing and the people involved are likely to face court action.