THOUSANDS of deadbeat mums are failing their kids by running up child support debts.
About 25,000 non-custodial mums are behind in child maintenance payments to dads who are doing the right thing.
There were many more deadbeat dads, but the Lone Fathers Association said yesterday authorities should take a harder look at mums who failed to pay child support.
"They should hound them like they do the dads," the association's Barry Williams said.
He said many non-custodial mums hid incomes, like deadbeat dads, by earning cash and understating business profits.
Child Support Agency figures, provided exclusively to the Herald Sun, show there are 90,562 mums across Australia with child support obligations.
Almost 10,000 are more than $340 behind in their payments, and 14,700 have smaller debts.
There are 648,550 non-custodial fathers in Australia.
About 229,000, or 35 per cent, are behind in their payments.
Human Services Minister Joe Ludwig said all parents should do the right thing and support their children.
"It's unacceptable for any parent to have a child support debt - it is both parents' responsibility to meet the needs of their children," he said.
"While most parents do the right thing, it's clear there are many parents who are failing to meet their child support responsibilities and give their children the support they deserve."
The Council for Single Mothers and their Children said men were more likely to avoid paying child support.
"It's an obligation on any non-custodial parent, full stop," convenor Elspeth McInnes said.
"But the fact is, there are more men who are non-custodial parents. The other big difference of course is women are much less likely to be in the paid workforce and be on good earnings.
"There aren't a lot of high-rolling women out there who aren't paying."
But the Lone Fathers Association said non-custodial mothers were getting an easy ride from the Child Support Agency.
"They seem to have a culture where if you're female, it doesn't seem to matter," Mr Williams said. "With dads, they hound them and hound them and hound them.
"We just want balanced treatment for everyone."
He said the worst offenders of both sexes were business people, who were able to launder their money and hide it.
"There is a lot of women doing that, I can tell you," he said.