Correctional Services spokesman Manelisi Wolela has denied allegations that student leader Mcebo Dla.
South African heavyweight champion Osborne Machimana says his full potential will not be discovered if he fights mediocre opponents such as Jake Els.
Machimana from Limpopo, who fights out of Gauteng under Nick Durandt, will defend his title against Els at Emperors Palace on August 7.
The short and bulky challenger from Vanderbijlpark is ranked number one.
Their fight will top the seven-bout "Annual Prive Boxing Ball" which will be promoted jointly by Golden Gloves and Durandt's Boxing World and Converse.
Machimana last fought on December 1 when he was stopped by Shane Cameron in nine rounds for both the IBF Pan Pacific and the WBA Pan African heavyweight titles in New Zealand. Machimana and Durandt both warned Els to "pasop or else".
"I will knock him out within six rounds."
Machimana, one of the few skilful heavyweight fighters in the world, was expected to reach for the stars after winning the SA title from Anton Nel on a fifth round knockout in 2005.
Instead, his promising career took a nosedive when he lost two fights against Livin Castillo and Albert Sosnowski before labouring to outpoint Colin Abselom.