Inmates at a South African prison known as Sun City were treated to “strippers” as part of an official event.
Pictures circulating on social media show two scantily-clad women in thigh-high boots pressing themselves up against orange suited men at Johannesburg’s Medium B prison.
On Monday, the Department of Correctional Services confirmed the veracity of the photos.
A full investigation was under way, James Smalberger told journalists.
“We can never tolerate what we have seen on the social media since Saturday,” Mr Smalberger, the acting national correctional services commissioner, said.
Thirteen officers are being suspended and will face the “full might of our code of conduct”, he added.