The DPI's director of invasive plants and animals,Dr Andrew Sanger,said the outbreak was contained to one colony at this stage,while"intensive surveillance"was being conducted within 2km of the initial discovery.

While the government works to contain the exotic ants,Mr Cox said the outbreak may have spread."It may be in the suburbs already - we don't know,"he said.

Since Australia's first outbreak of fire ants in Brisbane in 2001,federal,state and local governments have spent $281 million trying to eradicate them. In 2009 a Queensland government report said fire ants could cost south-east Queensland $43 billion over 30 years if they were not contained. The national figure would be much higher.

Mr Cox called for an increase in funding for eradication efforts to stop the ants spreading in Sydney and Queensland."You only get one go at this[eradication effort],"he said.