A former top Queensland judge has called for reform of a century-old legal loophole that can allow accused rapists to walk free, saying it is a "hangover" from outdated attitudes to women.

Key points: New academic research shows the "mistake of fact" defence has been used by violent repeat offenders

New academic research shows the "mistake of fact" defence has been used by violent repeat offenders Bond University law professor Jonathan Crowe and lawyer and author Bri Lee say the defence should be abolished

Bond University law professor Jonathan Crowe and lawyer and author Bri Lee say the defence should be abolished The Queensland Women's Legal Service has pushed for the reform since last May

Retired supreme court justice Roslyn Atkinson said the mistake of fact defence could allow men to invoke rape "myths" to beat charges, denying their accusers fair treatment in the courts.

New academic research shows the defence, which argues a mistaken but honest and reasonable belief that sex was consensual, has been used by violent repeat offenders and in cases involving domestic violence victims, people with disabilities and children.

Justice Atkinson, who until November oversaw some of the state's biggest criminal trials during a two-decade career on the bench, is the most senior legal figure to back growing calls to change the law.

She told the ABC the mistake of fact defence "put the onus back on the idea that it doesn't really matter if you obtain consent, so long as you think you have".

Defendants could argue they reasonably believed a woman wanted sex because "for example, she got into the car with me, she met me for a date that was arranged online, she went for a walk with me, she allowed me to kiss her, she allowed me to touch her breast".

"[This] would lead to the unfair case that a woman has to make it perfectly clear that she's not consenting rather than the man having to establish that she has consented," Justice Atkinson said.

"I think it's probably a hangover from an old attitude reflecting myths about the way women behave and whether or not that's sufficient to give consent to what would otherwise be rape.

"I don't think it does reflect community attitudes, at least I hope not."

'Outdated myths' put focus on victim

Jayne*, a Gold Coast grandmother whose accused rapist was acquitted under the defence in 2012 despite causing her life-threatening injuries, said it was "just awesome" the former judge had lent her weight to calls for reform.

Retired supreme court justice Roslyn Atkinson said the current law did not reflect the community's attitudes. ( Supplied: Queensland Courts )

"I sure hope the government is listening because this problem is not going away anytime soon," she told the ABC.

"We need to make changes so that as victims, we have faith in our system that it is supposed to keep us safe and hold offenders responsible for their actions.

"What happened to me was unfair and we can't go back and change that. But I believe that if I don't speak out — with all the senior people that are speaking out — we won't get change."

In the most detailed academic study to date of mistake of fact in Queensland rape cases, Bond University law professor Jonathan Crowe and lawyer and author Bri Lee argue the defence should be abolished.

Professor Crowe told the ABC they came across "a particularly disturbing type of case" where defendants successfully argued mistaken belief in consent "where the complainant was actually asleep or was so intoxicated she wasn't even capable of giving consent".

"That's a particularly egregious example, I think, of the injustices in this area of law," he said.

"I think reform in this area is overdue and now is the time to act... to try and close this loophole."

Professor Crowe said "outdated myths" that could not be used to prove consent in Queensland "are brought back into the law through the back door" under mistake of fact.

He said a woman's previous flirting, visiting a man at home at night, or "freezing, which is a common psychological response to a violent attack" had all been accepted by the Queensland Court of Appeal as "a basis for upholding this defence".

"We found that many of the cases involved violent, calculated, repeat sexual offenders who are relying on this defence, either at trial or on appeal, to avoid accountability for their actions."

In their soon to be published paper, the researchers suggest the Queensland Government can embrace moderate reforms already in law in Tasmania and Canada if it meets political resistance to abolishing the defence.

Professor Crowe said this limits the defence where accused rapists are intoxicated, "reckless" or don't take "positive and reasonable steps" to confirm consent.

Brisbane author and lawyer Bri Lee says the "mistake of fact" defence should be abolished. ( Supplied: Alana Potts )

'Law needs to reflect modern attitudes'

Justice Atkinson said she didn't support abolishing the mistake of fact defence, but it could be changed to "a test of the reasonable person rather than what's reasonable for that person [the accused rapist]".

Justice Atkinson said rape laws had rightly changed in line with community attitudes throughout her career.

"When I was a law student, a man could not be held criminally responsible for raping his wife... whether there was domestic violence, whether the parties were separated," she said.

Children used to be especially disadvantaged when they didn't report sexual abuse immediately because their evidence "had to be corroborated".

Justice Atkinson recalled the shocking case of a young nurse in a regional Queensland city who was pack-raped in a park and left by the side of the road, only to be raped by another group of men in another park.

"The question on appeal was, was her distress after that caused because she felt guilty about having had sex with so many men, or because she'd been raped? She was in hospital for several weeks," she said.

"All those areas of the law have changed... and this [mistake of fact] is just another development that needs to be taken seriously.'

Attorney-general Yvette D'Ath told the ABC in a statement that "people who commit sexual assaults deserve to be held to account".

"On the question of consent, the Palaszczuk Government has sought submissions from legal stakeholders and their views are under consideration," she said.

They include the Queensland Women's Legal Service, which has pushed for the reform since last May, and the Queensland Law Society, which then backed a review of the law.

Justice Atkinson said she did not think the Government opposed the change and "we have an Attorney-General who's very attuned to the need for law to reflect modern attitudes".

But no legal reform was ever "inevitable", she said.

"It requires people to speak about it, think about it, work on it and make the change."

*Not her real name