A KwaZulu-Natal magistrate has accused the Scorpions of stifling a police investigation into their former boss, Bulelani Ngcuka, and called on Justice Minister Brigitte Mabandla to place the issue before Parliament in an attempt to show how "high-ranking officials are being protected".

The Scorpions have recently been under attack from a number of parties, including the ruling African National Congress (ANC), over allegations that they abused their power in investigating various cases.

Last week ANC chief whip Mbulelo Goniwe slammed the Scorpions' "vindictive" investigation into the parliamentary travel scam.

Scorpions spokesman Makhosini Nkosi said Goniwe's comments did not "warrant a response".

Pitermaritzburg magistrate Ashin Singh intends to prove power was abused, and has threatened to launch a private prosecution if government decides not to take action against Ngcuka.

This would be the first case to be brought against Ngcuka and could herald further court applications from a number of people who claim they have been investigated and prosecuted without reasonable cause, among them mining magnate Roger Kebble.

Singh laid charges in November against Ngcuka, state prosecutor Billy Downer, deputy director of prosecutions Chris McAdam, attorney Percy Sonn and Scorpions investigator Clifford Marion for "defeating the ends of justice".

He claimed they had brought a false prosecution against him, while failing to act on information that the wrong people were in prison for the Richmond killings in KwaZulu-Natal in the late 1990s.

Although police have been investigating, Singh claims the national department of public prosecutions has tried to bury the probe, and prosecution is unlikely.

He says this case could have major implications for Downer, who is the senior state prosecutor in the Schabir Shaik fraud trial being heard in the Durban High Court.

Singh claims Downer led false evidence in the aborted criminal case against him in 2000 and should not be allowed to appear in court.

He says Downer is being protected "so that he may continue with his bid to discredit Deputy President Jacob Zuma".

The prosecutions department denies stifling anything. KwaZulu-Natal head of prosecutions Shamila Batohi says there is no police dossier in front of her on which she would make a decision on whether to prosecute.

Downer said on Friday he "had no knowledge about these charges", and would not comment further. McAdam referred queries to Scorpions spokesman Makhosini Nkosi.

Nkosi said: "To suggest we are dragging our feet on this matter is untrue, as the police have not completed their investigations."

The matter arose after the Scorpions arrested police director Erik Nkabinde and Capt Sipho Mbhele for the violence in Richmond during the 1990s. Singh says he told Ngcuka in writing the wrong people were in prison, but was later arrested by the Scorpions himself for allegedly failing to inform them of this.

It transpired that the wrong people had been imprisoned and after Nkabinde and Mbhele were acquitted, the real perpetrators were convicted. The case against Singh then fell apart, laying the groundwork for the current action.

With acknowledgements to Rob Rose and the Business Day.