Two men are likely to face court action after being found in possession of 3526 pipi taken from the Ōhiwa Harbour near Kutarere in the Bay of Plenty.
Ministry for Primary Industries spokesman Richard Ratapu said the men were caught with the illegal take during a routine inspection.
He said fishery officers were shocked by the find.
"These men's actions are extremely disappointing. They have shown a complete disregard for the daily legal pipi recreational allowance of 150 per person and have given no thought to the sustainability of Ōhiwa Harbour's pipi stocks.
"A quarter of the pipi were far too small to even consider eating."