ILLEGALLY imported chemicals could shut down an export industry or harm farmers, says the boss of Australia's plant science industry body.
But the Department of Agriculture, Fisheries and Forestry argues there is "no direct evidence" of a widespread problem.
This is despite China having significantly increased its production of ag-chemicals without increasing its consumption, and Interpol having issued a warning on the export of illegal chemicals in 2009. CropLife chief executive Matthew Cossey said illegal chemical products posed "serious risks".
"Even if it has the right active (ingredient), it might have toxins," he said.
He said a farmer might unknowingly use a stronger mix of chemical on an export product - putting the produce over acceptable residue limits.
Or the product might contain a chemical the farmer wasn't aware of, such as arsenic, contaminating the produce.
A spokesman for the department said there was "no direct evidence of a widespread problem relating to illegal agvet chemicals in Australia", but the issue remained a "concern".