The expression on Vusi Mona's chubby face was as engaging, charming and enigmatic as the Mona Lisa's.

Mona, former editor of City Press, was giving evidence before the Hefer Commission of Inquiry into whether the national director of public prosecutions, Bulelani Ngcuka, was an apartheid-era spy and had abused his office as a result.

It was a City Press report - the first publication of claims that Ngcuka had been investigated as an apartheid-era spy - which prompted President Thabo Mbeki to appoint the commission.

When senior counsel Norman Arendse, appearing for Justice Minister Penuell Maduna, commented on Mona's "meteoric rise" through the ranks, the former City Press editor's face lit up like a beacon.

And he kept smiling throughout seven hours of Arendse's cross-examination on Thursday.

He was apparently unaware that, just as a pride of lions drives its prey into the open, Arendse was quietly pushing him to put everything on the record, so that he would have nowhere to hide - no excuses or unstated information - when the kill came.

Ironically, it came after lunch, when everyone ought to have been feeling well-fed and comfortable.

It was the evidence leader, senior counsel Kessie Naidu, who went for the jugular.

Mona, who laid a complaint against Ngcuka with the Public Protector relating to an off-the-record briefing given by Ngcuka ended up conceding:

That he, then editor of City Press, had "recklessly" handled the original story alleging that Ngcuka had been investigated as a spy.

That the sub-heading on the story, which stated as a fact that Ngcuka was a spy, was wrong.

That City Press's use, in another story, of the sentence "that Ngcuka was able to get a passport from the apartheid police even though he was convicted of high treason", effectively showed bias against Ngcuka because it was untrue and the facts had not been checked.

That his claim that Ngcuka had intended that the contents of the off-the-record briefing be made public was false.

A typical example of Naidu's approach came when he asked Mona about the story related to Ngcuka's passport and the treason claim.

Pointing out that Ngcuka had in fact been imprisoned in the late 1980s for refusing to testify in someone else's trial, Naidu asked Mona:

"Do you not see that there is a huge difference between saying someone was detained on suspicion of treason or of negligent driving - or for that matter of urinating in a public place?

"How can you resist the suggestion that the publication of the stories [about Ngcuka in City Press] was malicious and designed to mislead?"

The rapid shift in Mona's demeanour, from confidence to that of a defenceless animal, began when Naidu asked Mona about the Ngcuka briefing.

Naidu asked why Mona believed Ngcuka had not placed a restriction on the use of information.

"Why did he ask you to put your pens down?" Naidu asked.

"Writing notes would point to Ngcuka as the source," Mona replied.

"You might charm others with that reply," said Naidu, "but the gentleman sitting up there (pointing to Judge Hefer) has heard many stories as fanciful as this one.

"It is nonsense. How would putting your pens down stop you from identifying him as a source?"

On Friday the agony continued for Mona, with Naidu asking further questions about why Mona had waited months before making the contents of the off-the-record briefing public.

And there were no smiles on Mona's face.

Estelle Ellis reports from Bloemfontein that Mona apologised to Ngcuka for publishing the spy claims.

Mona said; "I want to apologise unreservedly to Ngcuka, his family and to the National Directorate of Public Prosecutions for the pain the story caused.

"I still regard him as a man who can do his work."

Naidu pointed out to Mona that two documents, in which the contents of an off-the-record briefing between black editors and Ngcuka was published, contained an exact turn of phrase and chronology of events as were recorded by Mona in his notebook.

"It's a remarkable coincidence," Naidu said.

"How did this happen, Mr Mona. It points overwhelmingly to you being the author and distributor of this document."

Mona denied this and said it could have been done by a PR with whom he discussed the meeting.

Naidu did not accept this answer.

"I am suggesting to you that you are hiding something and if you are, come out with it."

Mona then conceded that he knew that the public realtions agent, Dominic Ncele, was also acting for the Kebble family and soccer boss Irwin Khoza - both of whom had been subject to a Scorpions investigation.

Naidu was outraged. "He told a spin doctor about his off-the-record briefing, surely this is improper."

With acknowledgements to Jeremy Gordin and The Star.