The amount of unpaid child support owed by 254,000 deadbeat dads has cracked $1 billion and the Government is employing private investigators to get it back.
Human Services Minister Joe Ludwig yesterday said non-paying parents would be under surveillance from next month to catch them out if they are being paid in cash.
A pilot program last year caught a number of non-paying fathers who claimed they could not pay.
One dad, who owed $12,000, was caught taking cash-in-hand payments from his employer. Another, owing $25,000, was caught trying to transfer ownership of his company.
Senator Ludwig said $162 million would be spent over the next four years to crack down on non-payers.
All parents involved in child support will have to lodge tax returns, count salary sacrifice payments as income and the Government will have new powers to seize assets where there is a child support debt.
Senator Ludwig said an army of private investigators would be contracted by the Child Support Agency to collect video evidence of non-paying parents, which could be used against them in court.
"It will provide visually compelling evidence that some people are not doing the right thing," he said.
"I want to reinforce this message to parents who fail to meet their obligations: if you don't do the right thing, you will be caught and have to face the consequences."
The crackdown comes just a week before a new child support formula is expected to cut the amount many single mothers receive from their former partners by between $10 and $100 a week.
Almost two-thirds of single mothers are expected to be left worse off under the formula, which is based on the costs of raising children.
Both parents' incomes will now be equally considered in working out child support owed. Fathers who look after their children one night a week will have their child support payments cut by 24 per cent.
Senator Ludwig was unable to say how many single mothers would lose under the new system even though his department has sent new child support assessment letters to them.
The architect of the changes, Sydney University law professor Patrick Parkinson estimated in 2005 between 50-60 per cent of single mothers would be worse off under the changes.
But he said 40-45 per cent of divorced dads would have to pay more child support.
Senator Ludwig said increases in the family tax benefit payments going to single mothers made it hard to work out whether they would be worse off under the new system.
"There will be swings and roundabouts with the system," he said.
"The new system will provide a better outcome for kids."