Jacob Zuma denies charges of graft, money-laundering and racketeering
A South African appeals court has ruled that the corruption case against ANC leader Jacob Zuma can continue.
A judge overturned an earlier high court ruling dismissing charges against Mr Zuma, saying the lower court judge had "overstepped" his authority.
State prosecutors said Mr Zuma "remains a charged person".
The ANC says Mr Zuma will still lead the party into elections due in the coming months, meaning he is the strong favourite to become the next president.
The 16 charges of corruption, money-laundering and racketeering stem from a controversial $5bn 1999 arms deal.
This whole issue of corruption, and other charges, do place a cloud over the [ANC] president
Peter Gastrow Institute for Security Studies
The ANC said that while it respected the Bloemfontein appeals court ruling, "it is important to note that this judgement has nothing to do with the guilt or otherwise of the ANC president.
"Nor does it make any pronouncements on the merits of the charges previously brought by the NPA [National Prosecuting Authority]."
It added that it and Mr Zuma reserved the right "to pursue all options available in law".
This means an appeal to the highest court in South Africa, the Constitutional Court, and a bid for a permanent stay of proceedings to prevent charges being pursued, says the BBC's Peter Biles in Johannesburg.
Mr Zuma has said he would only resign from public office if convicted. He could still be prosecuted if he became president.
Analysts say that while the ANC remains on course to retain its large majority in parliament, this ruling will make the campaign for the elections expected in April or May more difficult.
"This whole issue of corruption, and other charges, do place a cloud over the [ANC] president," said Peter Gastrow from South Africa's Institute for Security Studies.
June 2005: Sacked as deputy president
October 2005: Charged with corruption
December 2005: Charged with rape
April 2006: Acquitted of rape charges
September 2006: Corruption case collapses
December 2007: Elected ANC president; re-charged with corruption shortly afterwards
September 2008: Judge rules corruption case cannot proceed
January 2009: Prosecutors win appeal, opening the way for Zuma to be recharged
The bitter row over whether there was any political interference in the case has already led to several senior ANC officials leaving the party and setting up a rival group - Congress of the People (Cope).
The charges against Mr Zuma were dismissed on a technicality last September.
But the Supreme Court said Judge Chris Nicholson in the High Court "overstepped the limits of its authority" by saying there may have been political interference in the prosecution of Mr Zuma.
Judge Louis Harms said the suggestions "were not based on any evidence or allegation. They were instead part of the judge's own conspiracy theory and not one advanced by Mr Zuma."
The claims of political interference led Thabo Mbeki to stand down as president.
Mr Mbeki himself had called the lower court ruling "unfair and unjust" as he had not been able to defend himself in court.
Judge Harms likened Judge Nicholson to a football referee who "took his eye off the ball" and penalised not only players but also spectators - meaning Mr Mbeki, Associated Press news agency reported.
Mr Mbeki was replaced by Kgalema Motlanthe, an ally of the ANC leader.
Judge Harms delivers his ruling
Mr Zuma has unwavering support from the ANC leadership, the trade unions and Communist Party.
Mr Zuma's supporters have always said that a series of charges against him were part of a plot to prevent him becoming president.
The opposition Democratic Alliance had expressed concern at the lower court's ruling last year, saying it would bring a private prosecution if the NPA did not proceed.
Mr Zuma was sacked as South Africa's deputy president in 2005, when his financial adviser, Schabir Shaik, was found guilty of soliciting a bribe on behalf of Mr Zuma and jailed for 15 years in connection with the arms deal.
Mr Zuma then went on trial, but that case collapsed in 2006 when the prosecution said it was not ready to proceed.
He was also charged with rape, but acquitted in 2006.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.