Cape Town - Justice Minister Penuell Maduna yesterday defended national director of public prosecutions Bulelani Ngcuka's decision not to prosecute Deputy President Jacob Zuma amid growing opposition calls for Zuma's head.

At the same time, Home Affairs Minister Mangosuthu Buthelezi said the Scorpions should have proceeded with the prosecution, as it appeared that Zuma had been unfairly "tried by the media".

Maduna said the decision not to prosecute Zuma was not the first or last of its kind.

"You don't prosecute people just for the sake of prosecution. Once a prima facie case has been established, you consider the prospects of success first. A prima facie case does not necessarily constitute proof beyond reasonable doubt in a court of law," Maduna said.

At a weekend media conference, Ngcuka said Zuma would not be prosecuted, despite indications that there may be a corruption case for him to answer.

Buthelezi said: "I think the way the Zuma saga was handled was not fair. The judicial process ensures the right of each man to have his day in court."

But to say there was a prima facie case, but not enough evidence for a conviction, was "talking from both sides of your mouth", Buthelezi said.

Meanwhile, Zuma continued to proclaim his innocence.

"The presidency has noted the media reports relating to the charge sheet of (businessman and Zuma's financial advisor) Schabir Shaik and references made in it relating to the deputy president's financial affairs," his office said.

"The deputy president wishes to reiterate that he is not guilty of any wrongdoing or corruption, either relating to the arms deal or his financial affairs."

Meanwhile, Democratic Alliance leader Tony Leon said the fabric of South African society and democracy were at stake.

"If the deputy president simply remains in his post he will become a liability . The integrity of SA's legal system is now being questioned at home and abroad."

He attacked Mbeki's "unconscionable silence and inaction" over the saga, and said it was untenable that a state of open political warfare existed between the office of the presidency , Maduna and Ngcuka .

United Democratic Movement leader Bantu Holomisa said he shared these sentiments but called for a fully fledged judicial commission of inquiry into the arms deal.

"The president and the ANC must realise the interests of the country must supersede the interests of the party and the individual. It is not just Shaik that is on trial, it is Zuma as well as government and the African National Congress' commitment to the ethics of good governance.

"Zuma must go . He must resign or be fired ," Holomisa said.

With acknowledgements to Linda Ensor and the Business Day.