Two people have been busted trying to smuggle more than 100 live fish into Australia.
The 122 fish had not been declared before being found in plastic bags filled with water in the duo's luggage at Melbourne Airport.
The bags had been selected for inspection based on intelligence, with the Department of Agriculture, Water and the Environment and Australian Federal Police involved in seizing the aquatic animals.
Head of Biosecurity Lyn O'Connell said smuggling fish can have significant ramifications.
"Live fish can carry and transmit parasites, bacteria and viruses that could affect our native aquatic wildlife, and our $3 billion fishing and aquaculture industries," she said.
"They may also be considered a biosecurity pest and be damaging to our unique aquatic environments and ecosystems," said on Thursday.
Authorities cannot reveal where the passengers travelled from while the case is under investigation.