After its first meeting since Zuma was elected head of the party last month, the ANC's National Executive Committee (NEC) questioned prosecutors' handling of the charges of corruption, fraud, money laundering and racketeering against Zuma.

"The meeting expressed concern and grave misgivings about the timing of these charges and the general conduct of the NPA (National Prosecuting Authority)," ANC Secretary-General Gwede Mantashe told a news conference.

Mantashe said the NEC had reaffirmed its support for Zuma, saying it had full confidence in him.

The charges were announced barely two weeks after Zuma defeated President Thabo Mbeki to become leader of the ANC, the dominant party in South Africa.

The prospect that Zuma could be embroiled in a lengthy trial that may overlap with the next general election in 2009 could fuel investor concerns about political stability in Africa's largest economy.

The charges also raised the possibility that the ANC would come under pressure to seek an alternative presidential candidate.

If he is not jailed, Zuma is all but certain to become South Africa's next leader, given the ANC's grip on power since the end of apartheid in 1994.

Zuma, 65, has said he would only step down if a court finds him guilty. He has proven resilient in the face of controversy, making a remarkable political comeback despite earlier corruption charges and a rape trial in which he was acquitted.

ANXIOUS INVESTORS

Investors have been eagerly awaiting clues on the NEC's economic strategies after Zuma took charge.

Zuma's support among left-leaning supporters in powerful unions had raised concerns that he would steer away from policies fuelling an economic boom. He has told investors there is no need to worry about major changes in the economy.

Mantashe did not give any details on the issues, saying only that committees were being formed to set policy.

Zuma is due to stand trial in August.

Prosecuting Zuma could further divide the ANC -- suffering the worst split in its history -- and hurt his chances of succeeding Mbeki, who must step down in 2009.

Zuma's supporters accuse Mbeki of using state institutions such as the National Prosecuting Authority to protect allies and purge opponents, allegations he denies.

ANC leaders didn't hide their anger at the press conference, questioning the NPA's integrity.

"The political spin on the case is undeniable," said ANC Treasurer-General Mathews Phosa. "And if you think the ANC does not know what is happening you are making a very big mistake ... This case is very politically inspired."