Tina, whose name has been changed for privacy reasons, left her husband a couple of years ago.
"Probably the final straw was a head injury and a hospital admission," she said.
While the physical violence has stopped, the financial abuse has not.
She is supposed to receive $200 a month in child support, but payments stopped six months ago.
"I am probably earning half of what he's earning with full-time care for our child," she said.
"He contributes nothing. It is a struggle month to month to pay the bills."
Child support is supposed to ensure parents share the costs of raising their children, even after separation.
A Swinburne University report has found some parents are using it as a weapon to financially abuse their ex-partners.
Kay Cook said some parents minimise their income, fail to lodge tax returns or even threaten to not return the children.
"Child support is one of the few tools that really malicious ex-partners can use to have ongoing control of their ex-partner," explained Professor Cook.
There are more than 660,000 separated families in the child support system, according to Services Australia. About half of those payments are collected by the agency while the other half are transferred privately.
When it comes to the paying parent, around 20 per cent are required to transfer the minimum annual rate, around $8.80 a week.
Twenty-two per cent have not lodged a tax return and 24 per cent owe a debt to the receiving parent.
Government assumptions leading to loopholes being used
Jo, whose name has been changed for legal reasons, has been a single mum for a decade.
It has been a struggle to live on a single income with two kids.
"There is nothing in place to ensure that costs are shared," she said.
"So he is able to not have any other obligation than $50 per child per week. And he was able to sit back and say, 'well that's all I've been asked for, that should cover everything'."
"You've got children who are just going to miss out," said Terese Edwards from the National Council of Single Mothers and their Children.
"It can include, sadly, just the ability to play sport, to go on school camp, the have the latest up to date books."
The child support system is also closely linked to Family Tax Benefits, which means a single parent's benefits may decrease, whether their child support payments were received, or not.
"There's been loopholes built into the system where half of the population transfer payments privately, so there's no government oversight of what's being paid," explained Professor Cook.
"And the problem is that the government assumes that those payments are 100 per cent compliant."
The report's key recommendations include decoupling social security from child support, compelling parents to lodge tax returns and linking payments to credit ratings.
The Minister for Social Services Amanda Rishworth, said in a statement that, "Financial abuse comes in many forms and may not be straightforward".
"We are committed to ensuring government systems don't exacerbate any abuse, including financial."
The government will review the system and re-establish a child support consultation group this year.
