Low staffing rates have been blamed for a protest at Adelaide's high-security men's prison over the weekend.
But unions and the new South Australian opposition differ on what caused the staff shortage and what should be done about it.
Inmates at Yatala Labour Prison tore sinks off walls, ripped metal sheeting in cells and strew rubbish in corridors, in protest against a lockdown caused by low staff numbers.
Inmates were forced to remain in their cells during lunchtime on Saturday.
Public Service Association of South Australia assistant secretary Natasha Brown said staff shortages had become a regular occurrence under a policy of the previous government.
She said it was because of "crude cost savings through determining what would be the minimal amount of staff required at each jail and implementing that".
"It's not an ideal situation for there to be regular lockdowns — if our prisons were staffed safely and adequately, this would not be a common occurrence," Ms Brown said.
"Quite naturally, prisoners are going to become quite agitated."
Department for Correctional Services chief executive David Brown said the prison returned to normal on Sunday after a lockdown all day on Friday and Saturday.
"That's standard response when the staffing levels dictate we can't safely operate the prison in an unlocked mode," he said.
He said it was in response to a "significant number" of staff isolating because they had COVID-19 or were close contacts of people with coronavirus.
Opposition wants 'full review'
Liberal MP Tim Whetstone was a minister in the government toppled last month.
He said the government should still recruit more workers for the state's prisons.
"The opposition are calling on the government to increase staff numbers as well as put a review in place so this incident does not occur again," Mr Whetstone said.
"Severe damage to these jails – I think we need a full review so this incident does not happen.
"We will continue to see stress putting our prisoners and staff in danger, if not serious death."
Mr Brown said about 90 staff had been recruited over the past year but many had yet to complete their training.
He said the protest was limited to one unit, with items thrown through the traps in cell doors when the holes were open at lunchtime.
Prisoners who caused damage would be charged, he said.
Correctional Services Minister Joe Szakacs has been contacted for comment.
