Dirty tricks cannot be allowed to derail the investigation into arms deal corruption. Perhaps even more important, they must not be allowed to degrade our national prosecutions authority. The unproven claim by former transport minister Mac Maharaj and others suspected of questionable dealings in state contracts that prosecutions director Bulelani Ngcuka spied for the apartheid government is a transparent attempt to destroy Ngcuka's credibility and ability to lead an investigation into the allegations, especially those involving deputy president Jacob Zuma. Clearly, if he is hiding a shady past he is not suitable for a position of utmost probity. But if Ngcuka was suspected of being a spy, why did Maharaj and the others not object at the time of his appointment in 1998?

However, as we point out this week (Current Affairs), Ngcuka too has played a role in politicising the investigation and thus weakening his office.

Recent anomalies: he declined to prosecute Zuma despite claiming a prima facie case against him, thus toying with court authority. Earlier, he disclosed sensitive details of the case against Zuma to a select group of newspaper editors to try to solicit their support. And in statements this week he confuses loyalty to the state with that to his party, the ANC. Come, sir, stop playing the politician. If you have a case, try it - or quit.

With acknowledgements to the Editor and the Financial Mail.