A Vietnamese man has been arrested for allegedly trying to smuggle a rare and expensive fish into Australia in a bag hanging around his neck.

Key points: Asian arowana are an endangered species that are also known as dragon fish

Asian arowana are an endangered species that are also known as dragon fish A man was caught allegedly trying to import one at Adelaide Airport

A man was caught allegedly trying to import one at Adelaide Airport He could face 10 years in jail or a fine of up to $210,000

In a statement, the Australian Border Force (ABF) said the 34-year-old man, who was on a flight from Malaysia, was arrested at Adelaide Airport last Tuesday while allegedly trying to import a fully red Asian arowana fish into Australia.

"The fish was referred to the Department of Agriculture and Water Resources for identification and to assess the biosecurity risk," they said.

"It was determined to be an endangered fully red Asian arowana, the trade of which is controlled under the Convention on International Trade of Endangered Species, to which Australia is a signatory.

"The fish had to be humanely euthanised, as illegal imports of exotic animals can introduce serious pests and diseases that pose a significant biosecurity risk to Australia."

The fish in its bag at Adelaide Airport. ( Supplied: ABF )

The fish and the bag of water were discovered in a frisk search.

The man was then arrested and is expected to appear in the Adelaide Magistrates Court on May 15.

Asian arowana are also known as dragon fish.

ABF Chief Superintendent Brett Liebich said the agency would do everything in its power to disrupt and deter the illegal trade of animals.

"The ABF is committed to stopping the trade in rare animals and protecting our delicate natural wildlife from the potentially devastating impact of foreign diseases and predators," Mr Liebich said.

"The ABF takes the illegal wildlife trade seriously and we will continue to work collaboratively with our partners to detect, disrupt and deter illegal activity at our borders."

The maximum penalty for wildlife trade offences for individuals is 10 years' imprisonment and a fine of up to $210,000.