A woman spent a further four years in long-term seclusion in a NSW forensic hospital even after her conditions were deemed unacceptable by senior management, an inquiry has been told.
The Disability Royal Commission has been hearing the story of Melanie, the pseudonym given to a woman with an intellectual disability who was kept in isolation at the NSW Forensic Hospital after transferring from prison.
NSW Justice, Health & Forensic Mental Health Network chief executive Gary Forrest first learnt of Melanie's extended seclusion shortly after taking on the role in 2016, the hearing was told.
Mr Forrest agreed her situation should never have gotten to the point it had when he assumed the position, and should have stopped as soon as possible.
"Those seclusion rooms are designed for short-term use, they're not designed for long-term seclusion," he said on Thursday.
Mr Forrest said he put in place a series of reviews into restrictive practices at the hospital, the facility's culture and its models of care.
"Through those reviews it gave me a very clear idea about what the constant themes were that needed to be addressed in order to reach the point where we don't have anybody in long-term seclusion," he said.
Melanie was moved from the isolated environment to a room on a sub-acute ward late last year.
While Mr Forrest didn't comment directly on whether he believed Melanie's treatment was lawful, he said the relevant policy had not been applied correctly.
He said staff were "quite fearful" of Melanie and it took a significant amount of time to address the fear through a culture change and shift in safety practices.
In an audio recording played at the hearing on Tuesday, Melanie said she had "stayed strong" despite sexual, physical and psychological abuse.
She lived in a number of different homes and institutions as a child, and commissioners were told she engaged in two "very serious" acts of violence as a teenager.
One resulted in the death of a staff member at the juvenile detention centre where she was being held and resulted in her transfer to an adult prison, counsel assisting Janice Crawford said.
She left prison in 2011 when transferred to a forensic hospital.
Commissioners heard Melanie has been kept in the hospital as a civil patient since 2012 when her limiting term, representing the custodial sentence imposed under typical circumstances, expired.
She lived in the isolated environment "almost constantly" for about seven years, until November 2020.
The eight-day hearing of the Disability Royal Commission will hear from 33 witnesses as it explores indefinite detention and the "cycling in and out" of prison by people with disability.