The arrest warrant against police chief Jackie Selebi was cancelled last year because the acting prosecutions boss Mokotedi Mpshe thought the Scorpions might undermine him and serve it while he was still reviewing the matter.

Mpshe, who filled in for suspended prosecutions boss Vusi Pikoli, initially considered letting the warrant lapse, the inquiry into Pikoli's fitness to hold office heard on Friday.

Director general in the department of justice, Menzi Simelane, said Mpshe was setting up an investigation into the case against Selebi, but did not know where the warrants were and was concerned about the implications for national security if these were served.

Simelane said he and Mpshe discussed various options on how to deal with the warrants.

"He did not trust definitely that [the Directorate of Special Operations] would act properly in dealing with this matter with the national interest in the context of what was going on around that time."

Simelane said they wanted to make sure there was no crisis at the time in the country.

Earlier on Friday, the commission of inquiry heard that Justice Minister Brigitte Mabandla should have been liable for an unlimited fine or imprisonment for up to ten years for trying to stop Pikoli from arresting and prosecuting Selebi.

Pikoli's lawyer, Advocate Wim Trengove, put it to Simelane that Mabandla had improperly interfered with, hindered and obstructed Pikoli in the execution of his duties.

This is in contravention of the National Prosecuting Authority Act.

The act stipulated that no organ of state and no member and employee of a state organ may improperly interfere in or obstruct the prosecuting authority or any members in executing the carrying out of their duties and functions.

It further provided that doing so is punishable by an unlimited fine or imprisonment of up to ten years, or both.

However, Simelane "disagreed wholly".

"I agree with you that improper interference is a crime. I do not agree that the minister improperly interfered as you suggested," said Simelane.

"Until I have satisfied myself that sufficient evidence exists ... you shall not pursue the route that you have taken steps to pursue," Trengove read in a letter from Mabandla to Pikoli.

"There is nothing ambiguous about that instruction at all," he told Simelane.

But Simelane replied: "If the letter is read in context, it does not only give that interpretation that you are alluding to."

Trengove asked him whether it would have been unconstitutional had the letter asked Pikoli not to proceed with the arrest and prosecution.

"I can't make that assumption, because that is not what the letter assumes," Simelane replied.

"It was a flagrant violation of the Constitution," Trengove put it to him.

"I don't agree," Simelane countered.

President Thabo Mbeki suspended Pikoli as the head of the National Prosecuting Authority on September 24 last year and Frene Ginwala, the former speaker of the National Assembly, was appointed on September 28 to head the inquiry.

At the time, Mbeki cited a breakdown in the relationship between Pikoli and Mabandla as the reason for the NPA head's suspension.

The hearings, which started on Wednesday, have been adjourned until next month.

Sapa