A correctional centre where a former prison guard sexually abused female inmates needs more than 300 extra cameras to meet security requirements.
But substantial government funding allocated to upgrade CCTV coverage in multiple correctional centres is also unlikely to bring inadequate electronic security systems up to scratch.
A special inquiry is examining the circumstances surrounding offences committed by former NSW correctional officer Wayne Astill.
In March, Astill was sentenced to a maximum 23 years in jail for the rape and indecent assault of nine women while working at Dillwynia Correctional Centre in Sydney's west.
The 67-year-old will spend at least 15 years and four months behind bars for abusing his position of authority to commit offences over several years until his suspension in 2019.
The Minns Labor government ordered an inquiry following allegations Astill's crimes were concealed by other staff and dismissed by high-ranking managers, allowing the abuse to continue.
The inquiry heard there were 195 cameras in the section of the Dillwynia centre where Astill's offending took place.
But Corrective Services NSW security manager Fergal Molloy told the inquiry that number was significantly below what was required to have a properly functioning system.
Mr Molloy said there should be about 400 to 500 cameras to ensure the area was adequately covered.
He requested $500,000 in government funding to upgrade CCTV coverage at Dillwynia but noted other facilities had shortfalls in electronic security.
"Last year we received $10.5 million of funding for electronic security upgrades, statewide," he said on Friday.
"So yes, we do have some areas of obsolescence, but we're addressing that as we go."
Asked if the allocated funding would be enough to ensure adequate electronic security in facilities with shortfalls, Mr Molloy said it would not.
"Our aim is to get all centres to meet the security operational functional standards statewide and we're on the way but we still have a little bit of a way to go," he said.
Each new camera costs about $2,500, depending on the infrastructure available at a centre and the type of camera required.
Mr Molloy said correctional officers initially resisted CCTV in prisons because they believed it would be used to "spy" on them.
However, cultural change had led to a shift in attitudes about the technology.
"We now have requests for cameras in locations ... staff now embrace security technology because they can see the benefits of having CCTV in their area for their safety and inmates' safety," he said.
