Correctional Services spokesman Manelisi Wolela has denied allegations that student leader Mcebo Dla.
Nurses and doctors' unions have hailed the appointment of new Health Minister Aaron Motsoaledi.
Motsoaledi replaces outspoken former Health minister Barbara Hogan.
The Democratic Nursing Organisation of South Africa's spokesperson Asanda Fongqo said: "We are confident that his appointment will bring the much-needed stability to the health sector in line with the ANC's Polokwane resolution to prioritise health."
The Hospital Personnel Trade Union of South Africa said: "We have confidence he will address the challenges faced by doctors since he was in the profession himself."