Government on Wednesday vehemently denied claims by Vusi Pikoli that former president Thabo Mbeki suspended him to prevent the arrest of police commissioner Jackie Selebi.

"It is wrong to say the president abused power. There was no abuse of power," the director general in the presidency Frank Chikane told parliament's ad hoc committee reviewing Pikoli's dismissal as national prosecutions chief.

"I was there. The president did nothing to stop Pikoli from arresting Selebi."

Chikane said Mbeki had merely acted to manage any potential security fallout when he asked the head of the National Prosecuting Authority (NPA) to wait two weeks before arresting Selebi on corruption and fraud charges.

"There was a great risk of something extraordinary happening to destabilise the country and it was the duty of the president to ensure the country was not destabilised.

Pikoli, who told the president he would agree to a one week delay, had been prepared to "create a major crisis for the country" and was therefore legitimately sacked from his post last month, he said.

"He was not looking at the national implications," Chikane said.

"That is the central issue to me and I get the impression that the national director was under pressure from elsewhere."

Justice Minister Enver Surty told the committee that like Mbeki, his predecessor Brigitte Mabandla had never sought to undermine the independence of the NPA.

A letter from Mabandla to Pikoli in September 2007 telling him not to "pursue the route that you have taken steps to pursue", was not an order to stay the arrest, but was merely badly written, he told MPs.

"It is unfortunate the way in which it was written because it does lend itself to the interpretation of interference.

"But if I read the Ginwala Inquiry right, neither the minister nor the president had acted in a manner intended to prevent the prosecution of Selebi."

In a gruelling day of testimony to the committee on Tuesday, Pikoli had accused both her and Mbeki of meddling in the case and said he was sidelined for refusing to lay off Selebi.

Pikoli was suspended by Mbeki on September 23, 2007, days after refusing to wait more than a week to arrest Selebi. Last year, the Ginwala Inquiry found that he was fit to hold office and should be reinstated.

But President Kgalema Motlanthe refused, citing remarks by former speaker Frene Ginwala that he had failed to show proper regard for national security.

The ANC-dominated ad hoc committee will decide by month's end whether to ask MPs to endorse or overrule Motlanthe's decision.