Correctional Services spokesman Manelisi Wolela has denied allegations that student leader Mcebo Dla.
One man's determination to root out corruption and lawlessness in the taxi industry has led to his death.
Thomas Dinkwetse, the deputy chairman of the Greater Kagiso Taxi Association (GKTA), was shot eight times in the head yesterday morning.
Dinkwetse, of Extension 6, Kagiso on the West Rand, had been trying to weed out crooked members of the association since the beginning of the year.
His wife, Sister, said the family suspect top-ranking officials of the association of being behind the murder.
"He always used to say goodbye when he left in the morning but he did not do that today," she said. "He would always hoot after he had closed the gate but that did not happen either.
"I suspect the killers may have entered our yard and waited for him to go out. Why else would he not hoot?"
The 49-year-old father of two sons aged 18 and 10 and a 21-year-old daughter owned five taxis, one of which he bought a month ago and was driving yesterday morning.
He drove from his home to Extension 14, where he was shot.
His car careened off the road into the yard of another house.
The homeowner, Jeffery Kgokong, said: "We are lucky the yard has a lot of scrap material or the minibus would have driven straight into the house."
He said he heard gunshots from a distance but the last three were fired when the car was in his yard.
West Rand police spokesman Captain Siphiwe Ndlovu said Dinkwetse was found with multiple injuries.
"Police have not made any arrests and investigations will continue," he said.