A dispute over the appointment of a contractor is at the heart of the delay in completing security upgrades at two prisons.
The dispute concerns the appointment of SA Fence and Gate to undertake maintenance works, following the installation of security fencing and information systems in SA's prisons.
News24 previously reported that the cost of the contract escalated from almost R477m to more than R1.5bn in just seven years.
The Special Investigating Unit (SIU) is investigating the contract, including the cost escalation. That investigation is set to be completed this month.
In response to questions, the Independent Development Trust (IDT), which is responsible for the contract, said the cost escalations were the result of variation orders approved during the implementation of the contract.
IDT spokesperson Phasha Makgolane said the cost of implementation had increased after the initial assessment of the 13 facilities was concluded. The scope of the project also increased, he said.
In a letter from the IDT to National Treasury in early 2018, seen by News24, the entity said that work was suspended at some facilities by SA Fence and Gate over non-payment issues.
SA Fence and Gate told News24 that the parties were trying to negotiate an amicable solution to the impasse.
In early 2018, the IDT told Treasury that over 17% of the work at the St Albans prison and over 21% of the work at Westville prison was still not finished because of the payment dispute.
The IDT has since told News24 that it terminated its contract with SA Fence and Gate because of issues surrounding the "irregular" appointment of the contractor. This is understood to be specifically regarding a contract to do maintenance work at the facilities.
That matter is in court and the parties are waiting for a hearing date, the IDT said.
Other issues leading to the cancellation of the contract, the IDT said, were the dissolution of SA Fence and Gate's joint venture partners, and counterclaims against the contractor for possible overpayment.
The IDT and the Department of Correctional Services are currently assessing how much work is outstanding at St Albans and Westville and they are in the process of appointing a new contractor, the IDT said.
The Department of Correctional Services previously said it would not comment on the issue as it was before the courts, but said that security at the facilities had not been affected.