The system has become worse in the past decade and needs a complete overhaul for the safety of women and children, the Family Court Accountability Network (FCAN) told a federal inquiry on Thursday.
"Mothers who disclose domestic violence and child abuse are losing their children at an alarming rate," founder Janine Rees told the inquiry into the relationship between domestic, family, sexual violence and suicide.
"Our members describe this as a trauma and cortisol rollercoaster, repeating for the length of a childhood."
She said lawyers were telling victim-survivors not to disclose domestic violence or child sexual abuse because "it goes very badly" for them in the family court.
Analysis of 20 Magellan List judgments, which involve complex family law cases with serious allegations of abuse, found 70 per cent of people who disclosed they were using violence were granted sole parental responsibility, she said.
Sole parental responsibility gives one parent the exclusive legal right to make major long-term decisions for a child without consulting the other parent.
Lived experience advocate Lily Fetter said the family law system had worsened in the past 10 years because of cultural and systemic factors.
She said coercive control was being used against victims of violence by perpetrators in the courts.
"Men who perpetrate violence are master manipulators; they view a partner who responds, reacts, or resists to their abuse in any way ... according to them, that's her being coercively controlling," Ms Fetter said.
"They attack her and frame her as the perpetrator, and they play the victim."
She said "cold swaps" of children were happening in courts across the country, where mothers bring their children to court, put them into the childcare facility, go to the courtroom and then get "marched out with security guards".
"She doesn't get to say goodbye to her children. She doesn't get to explain anything," Ms Fetter said.
"I would like to see the system change. It's horrific, it's inhumane."
Both Ms Fetter and Ms Rees advocated for Australia to move to an inquisitorial, child-centred family court system.
"A truly child-centred system would be inquisitorial," Ms Rees said.
"It would be led by domestic family sexual violence professionals who understand coercive control, who co-respond with police, but they need to have the powers to investigate.
"The structure is the problem. The culture is the problem."
The attorney-general's office took a number of the claims on notice and said training was offered to judges and lawyers on many of the issues raised.
"The current system in Australia is an adversarial system," First Assistant Secretary Family and Community Safety Samantha Byng said.
"Any movement to an inquisitorial system would be a significant decision to be made by government."
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