The Police and Prisons Civil Rights Union (Popcru) on Friday called for the Department of Correctional Services to immediately cease any work with Bosasa.
"They have not added any value in ensuring the DCS (Department of Correctional Services) lives up to its core mandate, which is to rehabilitate inmates. [Instead], they continued to corrupt individual decision-makers in the department at the compromise of service delivery," Popcru spokesperson Richard Mamabolo charged.
Mamabolo was reacting to the shocking revelations at the state capture inquiry on Thursday that implicated Bosasa CEO Gavin Watson as an alleged bribe and intimidation kingpin.
During former Bosasa executive Angelo Agrizzi's second day of testimony at the commission, a video clip showing evidence of "bribe money" was presented and ripped open the secret workings of Bosasa's dealings.
In it, Watson could be seen counting money and telling an employee who he should make monthly payments to.
Mamabolo said the revelations did not come as a shock.
"For us, this comes as no surprise, and confirms our long-held suspicions over the highly controversial relationship Bosasa has [had] over the years with the Department of Correctional Services."
These latest revelations confirm the findings in a Special Investigating Unit (SIU) report released back in 2009, which found that Bosasa officials had allegedly paid bribes to former Department of Correctional Services chief financial officer Patrick Gillingham to secure multimillion-rand tenders.
He said there were still many unanswered questions over the awarding of tenders to Bosasa for providing nutritional services to the department.
Mamabolo said subsidiary companies of Bosasa, Phezulu and Sondolo IT, erected fences and dysfunctional surveillance equipment at prisons across South Africa.
"All of these amounted to billions of rands."
He urged the National Prosecuting Authority (NPA) to "act swiftly against all those involved in this looting".
Agrizzi's testimony continued on Friday.