A Fiordland amateur fishing charter company has been fined for illegally catching and serving an estimated close to $250,000 worth of crayfish to customers.

Fiordland Cruises Limited has been sentenced and fined $60,000 on one charge under the Fisheries Act in the Invercargill District Court after being prosecuted by the Ministry for Primary Industries.

The company will not have to forfeit its vessel, Southern Secret, if it pays a redemption fee of $47,000.

The ministry received several complaints about charter vessels working in the Fiordland Marine Area including allegations that seafood meals were used to encourage paying passengers to take part.

An investigation found Fiordland Cruises Limited took and served 1630 crayfish onboard the 162 amateur fishing charters it ran between January and October 2023.

They would have cost an estimated $239,610 to $244,500 on the domestic market.

Fisheries New Zealand compliance regional manager south Garreth Jay said all charter operators were given clear information on the rules.

That included only passengers who caught fish recreationally could have it served to them on the vessel as a commercial business could not catch fish recreationally to serve to customers, he said.

When fishery officers boarded the Southern Secret, they found that passengers were served crayfish for lunch despite not taking part in fishing, and guests saw crew members clearing cray pots.

"The skipper told us that along with the chef, they would lift the craypots while passengers watched."

"This is illegal behaviour from a company that does not hold a commercial fishing licence and is not a Licensed Fish Receiver," Jay said.

"We expect those rules to be followed."