The incident is under investigation and for that reason Mr Kennedy was limited in what he could say about last Monday's events, but he commended staff, who were monitoring and negotiating with the inmate for hours.

"We instigated a plan straight away to lock down the centre and then started communications with the guy who was on the roof," he said.

"It was a really good outcome - there were no injuries to any staff and over a period of time he came down.

"It was a bit of a high-risk exercise, but because the staff here at Bathurst and other centres are highly trained, and we've also got the expertise of the Security Operations Group ... we worked towards a really positive outcome."

He added that measures would be put in place to mitigate the risk of this kind of incident happening in future.