NSW top cop admits 'strain' due to probes

Probes upon probe, front-page stories and the fallout from a decade-old bugging scandal have created "strain" at the highest levels of the NSW police force, its chief admits.

Police Commissioner Andrew Scipione fronted a NSW state parliamentary inquiry on Friday to deny he was responsible for leaking against a member of the top brass, Deputy Commissioner Nick Kaldas.

It comes after a Fairfax Media article on April 17 reported NSW Ombudsman Bruce Barbour was considering referring Mr Kaldas to the Director of Public Prosecutions for possible criminal charges.

The upper house inquiry is now examining that leak as part of its consideration of another probe - Mr Barbour's long-running Operation Prospect, which was launched more than two years ago in connection with a covert internal police corruption investigation in which more than 100 officers including Mr Kaldas were spied on.

Mr Scipione conceded the uncertainty around Mr Barbour's investigation had taken a toll on the force.

"Without a doubt - not just within the executive; within all of those that are affected by Prospect," he told the inquiry.

Mr Scipione was due to retire this year, but one week after the Fairfax article appeared, NSW Premier Mike Baird announced that Mr Scipione's term had been extended.

Asked if the April 17 story prompted concerns about an "ongoing campaign", Mr Scipione replied: "There has been an ongoing campaign that has been difficult to manage now for many, many years. This was just the latest instalment."

He also revealed he has been aware since December that Mr Kaldas could face charges, but denied sharing that information with anyone else.

The commissioner agreed that he wanted Mr Barbour's Operation Prospect probe resolved, "the sooner the better".

And he said the fact Mr Barbour was due to retire within days and would be forced to hand the unfinished investigation over to a new ombudsman would "potentially" prove to be a new source of controversy that could damage the force.

"I assumed and thought that we would have this matter resolved by June," he said.

The inquiry also heard on Friday from Tim O'Connor, a senior investigator with the NSW Crime Commission.

Mr O'Connor said in a letter to the inquiry that a journalist behind the story, Nick McKenzie, told him that he had been speaking to investigators involved in the ombudsman's inquiry.

Mr McKenzie has subsequently denied that the source of the information was a person from the ombudsman's office.

"I clearly am wrong, but I would like to say that that was a theory on my part and I deliberated long and hard before providing this," Mr O'Connor said.