The inquiry into allegations that national director of prosecutions Bulelani Ngcuka was a spy has gained momentum, with the appointment yesterday of PricewaterhouseCoopers to conduct the forensic investigation.

The pressure is now on for the committee, headed by Judge Joos Hefer, which is expected to begin public hearings on October 13.

Political parties are calling for a speedy end to the public spat between Ngcuka and Deputy President Jacob Zuma, which is seen to be damaging public confidence in the justice system.

Apart from the auditor, Hefer has appointed four other people to assist him with the investigation. All have been prohibited from talking to the media.

Democratic Alliance leader Tony Leon has criticised the Hefer commission of inquiry's terms of reference as being too narrow, saying they should be extended if the commission intends to fully address the allegations.

The allegation against Ngcuka is that he used his office to pursue political agendas against certain individuals. This resulted from his handling of the investigation of alleged corruption by Zuma.

Leon, speaking at the University of Natal in Durban yesterday, said the commission should be able to investigate whether Ngcuka was responsible for leaks by the Scorpions to the media; whether he convened off-therecord briefings for the media to discuss specific cases under investigation; and whether he was subject to political influence in deciding not to prosecute Zuma.

"We must be certain that the national prosecuting authority is conducting itself properly, and that the national director is not abusing his power," Leon said.

"If he (Zuma) is to emerge from the Hefer commission with a clean bill of health, then each of these questions must be investigated thoroughly."

Leon said that the constitution required the prosecuting authority to exercise its functions without fear, favour or prejudice.

The inquiry has been given the task of finding out: "Whether at any stage prior to 1994 Ngcuka was registered with the security branch or any other security service of any pre-1994 government as an agent under the code name RS452 or under any other code name; and acting as an agent for the security police and/or National Intelligence Service of any pre-1994 government".

According to a notice in the Government Gazette, these terms of reference can be added to, or amended, "from time to time".

Leon repeated calls for Zuma's resignation. Regardless of Zuma's innocence or guilt, that there was a prima facie case against him meant he could face a conflict of interest, Leon said. The constitution stated specifically that cabinet ministers should not be exposed to any situation involving the risk of a conflict between their official responsibilities and private interests.

President Thabo Mbeki had shown a "glaring absence of leadership", allowing the matter to tear apart the African National Congress, said Leon.

Meanwhile, the trial of Schabir Shaik, Zuma's financial adviser, is not expected to get off the ground in the Durban Magistrate's Court today, because the state wants the matter to be heard by the high court. The trial is expected to be delayed until early December.

According to the provisional charge sheet released at his first court appearance in August, Shaik and several of his companies will face two charges of corruption, one of fraud and one under the Income Tax Act.

With acknowledgements to Chantelle Benjamin, Linda Ensor and the Business Day.