A former NSW prisons boss has admitted there was a "catastrophic failure" at a state jail where a now-disgraced corrections officer sexually abused female inmates.
A state inquiry is examining the circumstances of sex offences committed by ex-prison guard Wayne Astill at Dillwynia Women's Correctional Centre, on the outskirts of Sydney.
Astill was jailed for up to 23 years this year for abusing his position and assaulting prisoners for several years until his suspension in 2019.
It was an open secret within the jail that he engaged in sexual acts with female inmates, the inquiry previously heard.
On Monday, the inquiry was told Astill committed more than 30 offences over three years against at least 13 women.
It heard there were multiple intelligence reports from the jail that raised concerns about the guard, but they were ignored.
"You've got ... a catastrophic failure at this jail, in terms of the result, would you agree?" Counsel assisting, David Lloyd, asked former NSW Corrective Services commissioner Peter Severin.
"Yes," Severin replied.
Mr Lloyd put to Mr Severin - state prison boss for nine years until 2021 - that there was also an "institutional failure" to deal with the reports.
"I agree," Mr Severin said.
The inquiry was told of resourcing issues in the prison system's investigations branch, particularly in 2018.
Retired judge Peter McClellan, who is helming the inquiry, submitted that a lack of resources enabled "serious issues to sit and not be looked at".
"That has never been brought to my attention, quite frankly," said Mr Severin,.
"If that was information that I would have been made aware of, with $2.1 billion budget you could have found resources to actually make sure that never happens.
"That being said I was certainly aware that there were resource pressures."
Mr Severin said he would have expected "that the investigations branch would have brought this ... criminal intelligence to the attention of their line management".
He agreed with Mr Lloyd's submission that a "proper review" by NSW Corrective Services was needed to find out what went wrong at the jail and if things still needed to be fixed.
The inquiry, set up after Astill's sentencing, has heard more than 300 extra cameras were needed to address security shortfalls in the section of the prison where his offending took place.
A final report is set to be handed down in December.
rap1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
Australian Associated Press