By SEAN MURPHY.
Australian prawn producers have been conducting secret audits across the supply chain to identify any substitution fraud.
Secret tests have found 96 per cent of prawns labelled as Australian were verified as true to origin.
The tests were done using trace element testing, a technology designed to detect gold fraud.
The industry says the tests should give consumers and fishers increased confidence in the product.
However, hundreds of tests over two years have failed to reveal any systemic problems.
The Australian Council of Prawn Fisheries and the Australian Prawn Farmers' Association are jointly funding the testing, which uses world's best technology developed to help law enforcement agencies detect gold fraud.
Perth-based company Source Certain and Curtin University improved the technology first developed by chemist John Watling in 1972.
"Let's just say that everyone's on notice," said Stefan Diacos from the Australian Council of Prawn Fisheries.
"If you're going to call it an Aussie prawn, we're checking."
"We need to be able to give and carry on with the consumer confidence, the fisher confidence."