President Thabo Mbeki knew three weeks before he appointed the Hefer Commission that Bulelani Ngcuka had been investigated by the ANC for being an apartheid-era spy.

This was revealed yesterday at the commission by former transport minister Mac Maharaj, who said he went to see Mbeki about Ngcuka at 2pm on August 23.

Maharaj, who offered no further details about the meeting, was giving evidence under subpoena. The Hefer Commission was set up in September to probe claims that National Director of Public Prosecutions Ngcuka had been a spy and had abused his power.

Maharaj made a scathing attack on Ngcuka, but failed to back up his spy allegations.

When he faced a grilling from the commission's evidence leader, Kessie Naidu SC, Maharaj was unable to refute charges that his evidence was tainted with bias as a result of bitterness about a Scorpions probe against him.

Maharaj eventually admitted that the only evidence or information he had about Ngcuka being a spy had been given to him late in 1989 or early 1990 by Mo Shaik, then an ANC intelligence chief.

Maharaj said Scorpions leaks to the media had led to attacks on his integrity.

"My integrity is the only thing I have in life and I am here to redeem it," he said.

Maharaj spoke of at least "five deadly sins" he believed Ngcuka had committed.

The main allegations were:

That Ngcuka had leaked information to the press in contravention of the National Prosecuting Act.

Maharaj had to hear from Sunday Times journalist Jessica Bezuidenhout that he was under investigation for corruption. He found the questions asked of him by the Scorpions and those asked by the Sunday Times "striking" in their similarity.

Maharaj also said that Ngcuka had had an off-the-record briefing with six editors at which he told them Maharaj's wife, Zarina, would be charged with tax evasion.

That Ngcuka had lied. He told Maharaj that his wife would not be charged with tax evasion, despite what he had told the newspaper editors.

Ngcuka had also denied that he was attempting to sort out the tension around the arms deal investigation by "mediation", when, in fact, he was.

That Ngcuka had tried to resolve the conflicts caused by the arms deal investigation by using Maharaj as a "tool" to convince Deputy President Jacob Zuma and his financial adviser, Schabir Shaik, to co-operate with the Scorpions.

Maharaj said, however, that he had been involved in drawing up the National Prosecuting Act and knew there was no room for mediation.

That Ngcuka had refused to exonerate an innocent man.

Maharaj said that even though the investigation against him had been finalised and nothing had been found, Ngcuka refused to say so in public until the arms investigation was concluded.

Overall, Ngcuka's smearing of certain people was destructive to South Africa's new democracy. "Such an abuse of power left unchecked can lead to our democracy being emasculated," Maharaj said.

He faced a challenging but polite cross-examination from Naidu.

What role did his bitterness about the Scorpions investigation against him play in his making the spy allegations, Naidu asked.

Maharaj insisted he would have brought up the spy allegations even if he had not been investigated by the Scorpions. But Naidu was unconvinced.

"Zuma, Schabir Shaik, KwaZulu Natal MEC Zweli Mkhize, Tony Yengeni and Allan Boesak all claimed to have been victimised. Why did you only mention the allegations when you were the one to be investigated?" Naidu asked.

Nor could he answer convincingly when asked whether he had "anything else but Mo Shaik's word that Ngcuka was an apartheid-era spy".

Asked whether he had told anyone else about the claim, Maharaj said he passed it on to the ANC in Lusaka, but heard nothing further.

Today, Maharaj was due to face further cross-examination.

With acknowledgements to Estelle Ellis, Jeremy Gordin and The Star.