United Voice Queensland, which represents prisons guards, says overcrowding, understaffing and cost-cutting have led to an increasingly dangerous environment for staff and prisoners at the Arthur Gorrie jail in Brisbane.

Union spokesman Damien Davie claims GEO, the US-based prison operator, "was putting lives at risk in order to win a state government tender to continue running the facility".

Corrections minister Mark Ryan said the government would "not be pushed around on this issue".

"I take the safety of everyone in our correctional system, be them staff, prisoners or the community at large, very very seriously," he said.

"The government announced last year that the tenders for private prison contracts are on hold subject to the investigations conducted by Taskforce Flaxton."

Taskforce Flaxton was set up by the Crime and Corruption Commission and uncovered corruption risks, including a failure to report corruption, inappropriate relationships, excessive use of force, misuse of authority, the introduction of contraband and misuse of information.

Mr Ryan said the government would consider CCC's finding before making a decision about private prisons.

The growth in prisoner numbers placed a strain on prison infrastructure, with sewerage failures occurring at both Brisbane Women's and Arthur Gorrie correctional centres in recent years

In 2017, GEO, the provider at Arthur Gorrie, declined a request to take more prisoners beyond the current contracted level of 1187 prisoners, or 135 per cent, due to concerns about staff and prisoner safety and infrastructure limits.

 - with Felicity Caldwell