A woman with a development disorder screamed with distress and lost almost half her body weight while she was locked up in solitary confinement for up to 23 hours a day, the ombudsman has found.

Key points: Victoria has no specialist facilities for female prisoners with an intellectual disability

Victoria has no specialist facilities for female prisoners with an intellectual disability The ombudsman says the case highlights a "service gap" in mental health and disability services

The ombudsman says the case highlights a "service gap" in mental health and disability services The woman was released from prison late last year and is living in a house funded under the National Disability Insurance Scheme

The woman, who was given the pseudonym Rebecca to protect her and her family's privacy, was held in a Victorian prison for 18 months because there was no suitable alternative accommodation for her.

Ms Glass found the woman's treatment breached Victoria's human rights laws and international standards on the rights of people with disabilities.

"Rebecca remained in prison simply because there was nowhere for her to go," Ms Glass said.

"We need to ask ourselves how a humane society can justify such treatment."

The judge in Rebecca's case said she might have spent a month in prison had she pleaded guilty. ( ABC News: Emily Bissland )

'No practicable alternative in the circumstances'

Rebecca, who was 39 when the ombudsman became aware of her case in July last year, was remanded in prison in 2016 after being charged with breaching an intervention order taken out by her family, and resisting police.

She was later found unfit to stand trial and not guilty because of mental impairment.

Under Victorian law, people in Rebecca's situation must not be detained in prison unless "there is no practicable alternative in the circumstances".

While the men's prison system in Victoria has a specialist unit for prisoners with an intellectual disability, no such facilities exist for women.

Because of this and authorities' concern about releasing her into the community because she had no housing or support services, she was held in Victoria's main women's prison, the Dame Phyllis Frost Centre in Ravenhall, west of Melbourne.

The prison officer who processed her arrival at the centre noted she "presented as extremely unwell" and records from her first few days in the prison said she behaved erratically, refusing food, yelling, crying and asking for her father.

Rebecca was moved back and forth between the prison's management unit — used for women who commit disciplinary offences in prison — and its mental health unit, and was locked in her cell for up to 23 hours a day.

Rebecca developed bruising from sitting on the toilet after the prison removed the toilet seat from her cell. ( Supplied: Victorian ombudsman )

Cell provided little to do during lockdowns

When she was returned to her cell, Rebecca would scream with distress for hours on end, her guardian from the Office of the Public Advocate told the ombudsman.

In the mental health unit she was moved between two cells, one of which did not have a television.

The cells had little more than a window, bed, toilet and shower.

The report said there was little to occupy her during lockdowns.

She was given a toy cat and a velvet teddy, and would soothe herself by combing her hair.

The prison initially gave Rebecca magazines to read because she liked the royal family, but stopped providing these because she was tearing them up and blocking the toilet.

Her supply of toilet paper was limited for the same reason.

The prison removed toilet seats from her cell because she broke them, and she developed bruising on her buttocks from sitting directly on the toilet bowl.

Rebecca's guardian told the ombudsman: "[Rebecca] was bored … I'd be [breaking things] if I was locked in a cell for 24 hours … it's not entirely surprising that's what happened".

She sometimes refused food and lost over 50 kilograms — half her original body weight — in her first seven months of her imprisonment, before her weight stabilised.

Many days Rebecca was only allowed out of her cell for an hour. ( ABC News: Emily Bissland )

'Like looking after a kid'

Rebecca needed support for her personal care, but at the time the prison did not have a system for providing such support to prisoners with disabilities.

"[It] was like looking after a kid," an officer from the mental health unit told the ombudsman.

"When [Rebecca] first came to the unit, she didn't even know how to use sanitary items. She didn't wear clothing … she was scared of the shower … [she] wouldn't use toilet paper."

On their own initiative, officers went into Rebecca's cell to mop her floors, strip her bed and do her laundry.

"In all honesty I hope we don't ever have to have someone like [Rebecca] here again because I don't think prison is the place for her … [but] I think she got the best care she could ever have got in the prison environment," the officer told the ombudsman.

After 18 months in prison, Rebecca was released in late 2017 after government agencies found a house for her, funded under the National Disability Insurance Scheme.

The judge in her case said she might have been sentenced to a month in prison had she pleaded guilty and been sentenced.

Deborah Glass said fixing the issue should be a priority for the party that wins November's state election. ( Supplied: Ombudsman's office )

Rebecca's case not isolated: ombudsman

Ms Glass said Rebecca's case highlighted a "service gap" in mental health and disability services.

"Professionals agreed she needed support, but no one could agree on who was responsible," Ms Glass said.

"Although efforts are now being made to integrate her into the community, both she and society are still paying a high price."

Ms Glass said Rebecca's case was not isolated.

"We heard many more stories, some as sad as Rebecca's, of people with significant disabilities who had spent long periods in prison," she said.

"These stories highlight both the trauma of incarceration on acutely vulnerable people, and the threat to community safety in failing to provide a safe and therapeutic alternative to prison.

"The state must do more to invest in secure therapeutic facilities — in the words of a forensic psychiatrist we spoke to, Victoria needs a community facility that is both clinical and lockable.

"Whoever forms government in November, fixing this must be a priority."

A Victorian Government spokeswoman said it would consider the report's recommendations.

"There are a small number of people in the justice system who have extremely complex needs, and the department is always working to improve responses to these cases," the spokeswoman said.