Four Christchurch cockle rustlers were sprung with more than 10,000 of the shellfish stuffed into sacks.
It was the biggest illegal haul ever discovered in Canterbury.
The rustlers, Baoyi Mao, 24, Xue Jin Mao, 53, Wencoi Mao, 22, and Xihuo Lu, 46 admitted possessing more than three times the daily recreational limit of cockles, when they appeared in the Christchurch District Court yesterday.
They spent three hours at the Ashley River gathering 10,548 cockles, which they stashed in two vehicles, a 2006 Toyota van and a 2007 Landcruiser.
Each rustler was fined $2000 and the two vehicles were forfeited to the Crown.
Ministry for Primary Industries district compliance manager for Canterbury and Westland Peter Hyde said it was the largest haul he could remember in the area and could be the largest illegal haul in New Zealand for many years.
"It took the four officers over an hour to count what turned out to be 10,548 cockles."
Mr Hyde said he was delighted the four were caught thanks to to a tip-off from the public.
The daily limit for recreational cockle gathering in Canterbury is 150 per person.