Former City Press editor Vusi Mona did not see it coming.

It took Norman Arendse, SC, appearing for Justice Minister Penuell Maduna, seven hours of cross-examination to corner him.

Then leader of evidence Kessie Naidu, SC, moved in for the kill and Mona surrendered.

I was wrong, Mona conceded three times.

Mona was referred to the Hefer Commission in Bloemfontein to give evidence after filing a complaint against National Director of Public Prosecutions Bulelani Ngcuka with the Public Protector. His complaint was based on an off-the-record briefing given by Ngcuka to a group of editors.

It was City Press that first published the allegation that Ngcuka had been an apartheid spy.

Naidu explained to Mona that he should ensure that what he said was the truth.

Referring to Mona's testimony that Ngcuka had asked the editors after about 15 minutes to stop taking notes, Naidu said: "Why did he ask you to put your pens down?"

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

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

Mona looked bewildered.

Naidu: "It is nonsense. Surely, Mr Mona. Let me prove it to you by asking a question. How would putting your pens down stop you from identifying him as a source?"

Mona: "I was wrong about it."

Naidu: "Was it wrong or was it false?"

Mona: "I would say it was wrong."

Naidu: "You should know the difference between wrong and false. If you are man enough you will say it was false."

Judge Hefer (not looking happy): "Let me ask you this. Why did you give me a wrong reply?"

Mona (shifting in his seat): "Mr Chairman, the way the question was put to me - I did not understand the question."

Naidu: "If you did not understand the question, why did you say the answer was wrong? Let me tell you why it is wrong. When Bulelani Ngcuka told you to stop writing his purpose was that he should not be quoted and the information he gave you should not be published. That is the only inference that can be drawn from it."

Mona: "Correct."

Naidu: "Then don't you agree that your answer was false? You cannot have your cake and bite and eat it. Why are you giving wrong evidence? Tell me if you cannot answer and I will ask my next question."

Mona: "I cannot answer."

Naidu: "My next question is: why can't you answer my question? You came here. You took the oath to speak the truth. Now you cannot answer a simple question. Why did you tell us something that was wrong?"

Mona: "I just responded."

Hefer: "Did you answer without thinking?"

Mona: "No, I just responded."

Naidu: "So you just talk without thinking. Please try to desist from giving wrong evidence."

Naidu asked Mona if his impression of the briefing was that Ngcuka lacked independence. Mona said "yes".

Naidu: "You wrote in this column that Ngcuka is displaying a 'fierce sense of independence'."

Mona: "I also said that until it can be proved that Ngcuka abused his office, he must be left alone."

Naidu: "You know, Mr Mona, you must come assist me. You really help me. Now you just confirmed the inconsistency I was pointing out to you."

Mona: "It is inconsistent."

Naidu: "When you say it is inconsistent, you will agree that your answer was wrong."

Dealing with City Press's first spy story, Naidu referred to Mo Shaik's intelligence report, which the paper had in its possession and which said there was "a reasonable basis to suspect Ngcuka of being Agent RS452".

Naidu: "It is distinct from saying he was Agent RS452?"

Mona: "Yes."

Naidu: "The latter would be a very damaging impression."

Mona: "Yes."

Naidu: "Read the subhead on that front page story to us."

Mona: "Scorpions boss named in report as apartheid Agent RS452."

Naidu: "That is wrong."

Mona: "I'll concede."

The SA National Editors' Forum, in a statement last night, lambasted Mona for breaching "all the rules of professional conduct" of journalism by attending the off-the-record briefing, publishing what had been discussed in confidence and repeating it to the Hefer Commission.

"The principle of confidentiality of sources and information is regarded as sacrosanct by journalists, many of whom have gone to jail to uphold it."

With acknowledgements to Estelle Ellis an d the Cape Times.