A global super pest that has settled into southeast Queensland has been accidentally imported into NSW, marking its first known incursion in almost a year.
Officials are now inquiring whether turf was falsely signed off as being treated for fire ants before crossing the border on Wednesday.
The ants were found shortly after the turf was laid at a private property west of Byron Bay, the NSW government confirmed on Thursday.
Red imported fire ants are considered by biosecurity experts as one of the worst invasive species to reach Australia, potentially causing more economic damage than cane toads, rabbits and feral cats combined.
Their painful bites also pose a major threat to the future of park barbecues and picnics.
Police joined the national eradication program in October to ensure access to all properties in the infestation zone.
The latest incursion at Clunes has fed into concerns about the growth of fire ant numbers within suppression zones in Queensland.
A suppression and compliance blitz was urgently needed, the Invasive Species Council said.
"'Fire ants are one of the world's worst super pests, and their unchecked spread will result in economic damage greater than that caused by cane toads, rabbits, feral cats and foxes combined," advocacy manager Reece Pianta said on Thursday.
Queenslanders are legally required to report suspected sightings of fire ants within 24 hours of their discovery.
But Mr Pianta said he had seen fields with hundreds of fire ant nests a stone's throw from turf farm production areas.
"This is a recipe for a national fire ant disaster," he said.
"To eradicate fire ants we can't kill most of them - we must systematically treat 100 per cent of the land in the infestation zone."
Before Wednesday, fire ants had only been found a handful of times and not since July in Wardell, with that nest related to an incursion in January.
Five-kilometre control zones remain around Wardell and South Murwillumbah.
The early discovery and ant life cycle stage involved in Wednesday's case means a similar zone at Clunes is unlikely.
NSW biosecurity officials received paperwork saying the lawn had been treated with fire ant killer and would now test the quantity used, a government spokesman said.
Under NSW law, turf imported from southeast Queensland must be treated with an approved fire ant killer - both on the commercial farm and at the point of lay.
The turf supplier has been temporarily banned from exporting to NSW while investigations continue.
The Australia Institute in September warned that without improved eradication efforts, fire ants could kill six Queenslanders and cost households $188 million a year.
Nationals leader David Littleproud has warned $268 million across four years in federal funding to eradicate fire ants was likely not enough.
Federal, state and territory governments have committed $1.28 billion by 2027 to tackle the ant menace.
Red imported fire ants have been eradicated from Australian states on seven occasions including in Gladstone, Port Botany and the Port of Fremantle.
