The National Network of Incarcerated & Formerly Incarcerated Women and Girls has urged an end to over-incarceration after the death of a young Aboriginal woman in Bandyup Women's Prison in Western Australia.

The WA Department of Justice said on Monday that the 35-year-old woman was found unresponsive in her cell early that morning.

It has been reported it was a single-occupancy cell. National Indigenous Times understands that single-occupancy cells are used for detained people under observation for mental health or other welfare concerns.

National Network spokesperson Debbie Kilroy said while "authorities have stated that preliminary reports indicate no suspicious circumstances, the National Network raise serious questions about the conditions in which she was being held".

"We do not yet know whether this woman was being held in solitary confinement, why she was in a single cell, or what circumstances led to her death," she said.

"What we do know is that prisons in Western Australia, and across the country, are dangerously overcrowded, placing immense strain on the women inside."

Lorraine Pryor, National Network member and founder of WA-based Aboriginal corporation, Voice of Hope, noted that overcrowding "creates conditions of heightened distress, isolation and neglect".

"It reduces access to health care, mental health support and meaningful human contact," Ms Pryor said.

"These conditions are not incidental, they are the predictable outcome of policies that continue to expand policing and imprisonment, including increasingly punitive bail laws that are driving the imprisonment of more women, many of whom are themselves survivors of violence and poverty.

"Aboriginal women are particularly impacted by these policies. They are the fastest growing prison population in Australia, and their deaths in custody continue to expose the ongoing violence of a system that was never designed to care for them."

The Network noted that every death in custody raises the same urgent question: "Why are we continuing to warehouse women in institutions that are incapable of keeping them safe?"

The Network said the only meaningful response to these ongoing harms is decarceration.

"Governments must urgently reduce the number of women in prison by ending the over-use of remand, repealing punitive bail laws, and investing in community-based supports," Ms Kilroy said.

"At the same time, while women remain inside prisons, governments must ensure that organisations led by women with lived experience of imprisonment are resourced to provide support to women inside prison. Peer-led support and advocacy are critical in ensuring women have someone they trust to turn to and in holding prison systems accountable for the treatment of those in their care."

National Indigenous Times has contacted WA Minister for Corrective Services Paul Papalia and the WA Department of Justice for comment.

More than 600 First Nations people have died in custody in Australia since the Royal Commission into Aboriginal Deaths in Custody brought down its findings and made over 300 recommendations for reform in 1991.

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