Video has emerged of One Nation Senator Malcolm Roberts saying the family law system sometimes left men in custody disputes with no option but to leave the system or "hurt the other person".

Key points: Mr Roberts's comments were made in a 2018 video with Steve Dickson and men's rights activist Leith Erikson

Mr Roberts's comments were made in a 2018 video with Steve Dickson and men's rights activist Leith Erikson Pauline Hanson's spokesperson said there were "uncomfortable" links between family courts and domestic violence

Pauline Hanson's spokesperson said there were "uncomfortable" links between family courts and domestic violence Domestic violence support groups say the comments send the wrong message to men and can be harmful to women

In a Facebook live video from March last year, Mr Roberts said "there's no excuse for violence" but claimed the family law system was responsible for driving men to lash out.

Mr Roberts helped party leader Pauline Hanson's successful push for a parliamentary inquiry into family law, which was announced by Prime Minister Scott Morrison this week.

Her appointment as the deputy chair of the inquiry sparked condemnation from anti-domestic violence groups after she claimed women frequently fabricated child abuse allegations against former partners in Family Court proceedings.

In the video on One Nation's Facebook page and on its website, Mr Roberts discussed family law with then One Nation Queensland leader Steve Dickson and men's rights activist Leith Erikson.

"There's no excuse for violence," Mr Roberts said.

"I know you agree with me Leith on that and you've counselled people against that.

"But when you're a father, and you can't get access to your kids, and you can't get access to the legal system properly, what else is there to do other than check out or hurt the other person?

"You can just see people just lashing out — the system is driving violence."

Mr Roberts said violence came in many forms, including emotional, psychological and legal. He encouraged men under stress to reach out for support.

Pauline Hanson's appointment to the inquiry has been met with fierce opposition. ( ABC News: Jed Cooper )

Language 'can be very harmful'

Executive officer of the NSW Women's Legal Service, Helen Campbell said the comments sent the message that men had no control over their behaviour.

"If they loved their child that much, how do they think having a violent or absent father is going to be helpful to that child?" Ms Campbell asked.

The chief executive of violence prevention group Our Watch, Patty Kinnersly, said she saw "worrying attitudes" among people in positions of power that fundamentally disagreed with violence against women but provided a justification for the male perpetrator.

"Language that inadvertently blames victims, excuses decisions made by perpetrators, or incorrectly suggests that factors like stress or mental health issues are drivers of violence, can be very harmful," she said.

Eva Cox, an adjunct professor in sociology at University of Technology Sydney (UTS), called the comments "appalling".

"Simply nobody who has any serious sense of who they are or what their role is as a parent would assume that using violence would be any solution," Ms Cox said.

In response to ABC questions, Mr Roberts said he was "appalled that you would even imply a reversal of my clearly stated meaning".

Eva Cox said the comments were "appalling". ( ABC News: Billy Cooper )

"For that reason I repeat for you my core point stated in my opening words: 'There's no excuse for violence'.

"We do not condone violence."

He said while the family law system contributed to violence, "the ultimate responsibility is with the violent individual".

A spokesman for Ms Hanson said "stating uncomfortable facts about links between the failing family law system and domestic violence is in no way condoning such behaviour".

He called for a "warts-and-all discussion" of the issue.

Men's rights activism and family law

Leith Erikson has been a significant influence on One Nation's family law policy and has claimed domestic violence statistics were manipulated in favour of women.

He is the head of the Australian Brotherhood of Fathers (ABF) group, which was accused of harassment and intimidation by Queensland state Liberal MP Ros Bates in 2017.

"They are a group of men who harass women, promote suicide and use fake statistics, all to drive their own warped agenda," Ms Bates said in parliament.

But ABF representatives said the group promoted men's mental health and welfare, and "gender equality" before the law.

Men's rights activist Leith Erikson has helped influence One Nation's policy on family law. ( Facebook: Leith Erikson )

In the Facebook video, Mr Erikson referred to how his group "produced policy" for One Nation ahead of the 2017 Queensland state election "to level the playing field and make domestic violence policy gender-neutral".

Mr Erikson has claimed, without empirical evidence, that 21 men died by suicide each week as a result of the stress of family courts and family access issues.

The Australian Bureau of Statistics does not collect data on whether male suicides were fathers or those experiencing relationship breakdowns.

But the "21 fathers" statistic has long been echoed by Mr Erikson's allies in One Nation.

In Ms Hanson's maiden speech in 2016, she declared "on average, three men a day … take their lives due to family breakdowns".