Correctional Services spokesman Manelisi Wolela has denied allegations that student leader Mcebo Dla.
President Thabo Mbeki agreed on Saturday to resign after the top echelon of his party, the ANC, asked him to step down.
The party's fateful decision is a harsh rebuke to Mbeki. He had first served the party as an acolyte in the nation's freedom struggle and later for two decades as one of its guiding lights.
The power - though not yet the presidency - now shifts to Jacob Zuma, who has promised to loosen the manacles of poverty from the millions still living in shanties.
Gwede Mantashe, the party's general secretary, said in a news conference that Mbeki had taken the news in his stride. Mbeki's office confirmed within hours that he would be stepping down "after all constitutional requirements are met".
An acting president will be appointed from parliament, likely within days.
According to South African law Zuma, who is not an MP, is ineligible to replace Mbeki. But Zuma is expected to run for parliament next year, and is then likely to become president. The elections are likely sometime between February and June.
Saturday's events bring to a close a nine-year presidency during which Mbeki accrued both celebration and disrepute.
He became internationally notorious for his views on Aids, joining maverick scientists in questioning whether a virus was the cause of the illness.
He led the resistance to antiretroviral treatment, acting as if the Aids epidemic were a defamatory plot against Africans and a con job by avaricious pharmaceutical companies. This intransigence, critics say, sent countless thousands to a needless death.
Last December Zuma defeated his former boss for the party's leadership in a vote that showed the party deeply split. With that victory, and with the ANC dominant in national elections, Zuma was solidly in line to become president next year when Mbeki's second term in office expired.
But many of Zuma's supporters, openly despising the president, wanted him gone sooner rather than later. A majority of the party hierarchy seemed to resist that view until a week ago when a judge's ruling in a corruption case that has long dogged Zuma tipped the balance.
In that decision the judge not only set aside the case against Zuma on procedural grounds, he pointed toward what seemed a pattern of political meddling in the matter by Mbeki's government.
That view seemed in agreement with conspiracy theories favoured by Zuma and his followers, and when prosecutors announced that they would appeal the ruling it appeared the case might yet be revived.
With inevitable delays for pre-trial motions an appeal could hang over Zuma until 2010, pitching the nation into a constitutional crisis with its likely president in the dock.
The country requires "closure on that chapter," Mantashe said, though it was unclear how the national prosecuting authority, which is nominally independent, could be relied on to halt it.
Mantashe took time to flatter Mbeki for his long service to the ANC and said, "This is not a punishment."
But it is hard to see Saturday's decision as anything other, unless it is to view the action as merely another chapter in what once seemed an unlikely conflict for power between two men who had been trusted allies, with the party selecting Mbeki as its president in 1997 and Zuma his deputy.
At the time Mbeki was deputy president of the country, Mandela its president. But some of the seeds of Mbeki's undoing were planted then.
Once in power, the party's leaders veered from their leftward leanings adopting policies of fiscal austerity that reassured the financial markets but postponed most efforts to aid the downtrodden.
By the time Mbeki assumed the nation's helm in 1999, with Zuma again as his deputy, those criticisms were increasingly strident.
Indeed, Mbeki was ever more remote and inscrutable. In 2001 he went on television to suggest that a coup might be in the works orchestrated by three of the ANC's most respected leaders: Mathews Phosa, Cyril Ramaphosa and Tokyo Sexwale. Behind the scenes, he told others that he thought Zuma had been a collaborator.
Therein began the rift that led to Saturday's decision to cut short Mbeki's presidency.
Mbeki had impeccable liberation credentials: the son of movement icon Govan Mbeki and protégé of longtime ANC president Oliver Tambo. An exile at 20, he was picked out by party elders as a first-rate intellect to be groomed as a leader. He studied economics at the University of Sussex and political theory at the Lenin Institute in Moscow.
Mbeki became fond of Saville Row suits, good scotch and ornate pipes. He was a master of bonhomie.
Zuma, the self-educated son of a Durban domestic worker, is physically imposing and street smart. He was locked up for 10 years on Robben Island in a cell near Mandela's. His talent for entertaining a multitude was equal to Mbeki's ability to leave the same people drowsy.
Zuma is popular among his fellow Zulus and many of the poor. Last December, after he defeated Mbeki for leadership of the party, many of those followers felt a sense of deliverance. - New York Times