A passenger from Vietnam arrived in New Zealand with live Siamese fighting fish.
The five fish in plastic bags were seized at Auckland Airport by biosecurity staff after the man declared "wet fish" on arrival forms.
"The traveller's English wasn't very fluent and we initially thought he was carrying frozen or dried fish," said David Sims, Ministry of primary Industries manager, Auckland Airport.
"It was a surprise when he pulled out the plastic bags."
The fish were "humanely euthanised", MPI said.