The Inland Revenue Department has set up a new team to chase down child support payments from parents who have left the country.
IRD says there are about 18,000 parents with outstanding child support payments living in Australia and almost 7000 in other countries.
It says 68% of the parents it deals with owe less than $10,000 but in one case a parent owes almost $49,000, which is currently being repaid.
IRD says most of the outstanding payments are dealt with by a government department in Australia but it has set up a new Direct Debt Team with access to Australian databases to track down those who aren't registered.
It can then work with Australian authorities through the courts, preventing people from leaving the country until they pay up.