Correctional Services said that “matters are under control” at Johannesburg’s Sun City Prison on Wed.
The Kwazulu-Natal social development department has assigned a specialised task team to probe the assassination of its anti-corruption manager Thembinkosi Dlamini.
Dlamini, 37, was shot dead at point blank range at the welfare offices in Ngewelezane, northern KwaZulu-Natal, last Wednesday. He had only been in Ngwelezane for two weeks.
Dlamini had been instructed to root out fraud and corruption at the social welfare offices.
The Ngwelezane office had been identified as one of the most corrupt in the province.
Department spokesman Mandla Ngema said: "The department is confident that the killer or killers will be brought to book.
"We cannot divulge too much at this stage. The investigations are at a very critical stage and our information is that the suspect or suspects are known."
Ngema said provincial social development MEC Meshack Hadebe's request that security be beefed up at Ngwelezane and other district offices after the attack was taken seriously.
"The MEC has called for swift security measures to be taken at that office and others in the province," he said. "Plans are being finalised. This is a priority and will be implemented as a matter of urgency."
Dlamini was buried at the weekend in Durban. His shocked colleagues are still receiving counselling following his daylight shooting at his workplace.
He is known to have put a stop to fraud and corruption among certain officials in the Ngwelezane office, identified by the department as one of the most corrupt in the province.
An angry Hadebe last week said he suspected that Dlamini might have discovered sensitive things in the Ngwelezane offices.