Tension between the Scorpions and the South African Police Service (SAPS) burst into the open yesterday, with police accusing the Scorpions of statements that are "completely devoid of reality" relating to a police probe into former Scorpions boss Bulelani Ngcuka.

In a hard-hitting rebuttal of recent comments by the prosecuting authority, police yesterday backed claims by a KwaZulu-Natal magistrate, Ashin Singh, that the Scorpions were stifling a criminal probe into Ngcuka.

Singh was arrested in 2000 by the Scorpions but later exonerated, an ordeal for which he laid charges in November 2003 against Ngcuka and senior prosecutions officials.

Singh claimed last week that the Scorpions were stifling the police probe into Ngcuka, a claim denied by prosecutions authority spokesman Makhosini Nkosi. He said police had not yet finished investigating Ngcuka, and that there was no completed docket.

Yesterday divisional commissioner Johan de Beer took the Scorpions to task, saying Nkosi's claim was "completely devoid of reality".

"The factual situation is that the SAPS has, since November 2003 … experienced extreme difficulties obtaining documentation relevant to the investigation from the Scorpions and the prosecuting authorities." He said the Scorpions had refused to hand over certain documents relating to the case, saying the files either "cannot be traced after a diligent search" or were "internal communications not to be used in the consideration of this matter".

Police spokesman Ronnie Naidoo said that if the Scorpions continued to stand in the way of the Ngcuka investigation, "we might have to take the legal route". Although he did not say so, this could even involve getting search warrants for the Scorpions' premises.

Nkosi yesterday stood by his statement, saying "it is the factual situation that there is no completed docket with the prosecutions department". He said he would look into De Beer's claim that the Scorpions were obstructing the case.

Although the Scorpions, which fall under the national prosecuting authority rather than the police, have built up a formidable reputation for tackling politically sensitive cases, including that involving Deputy President Jacob Zuma, police insiders accuse the unit of grandstanding and poaching "high profile" cases from the police.

The new claims about the Scorpions come at a critical time for the unit as government weighs whether or not to place the unit under the control of the police.

With acknowledgements to Rob Rose and the Business Day.