Ombudsman maintains right to silence at police bugging inquiry

The ombudsman has since 2012 been conducting an investigation into Operation Mascot, an anti-corruption phone bugging and surveillance operation carried out by the NSW Special Crime and Internal Affairs unit from 1999-2001.

Since Operation Mascot was made public and the investigation, known as Operation Prospect, was launched in 2012, it has set the top echelons of the NSW police force against each other.

Current deputy commissioner Catherine Burn oversaw the investigation, while her fellow deputy Mr Kaldas was one of its targets.

Up to 100 officers were monitored by Operation Mascot, and the inquiry has heard warrants for surveillance were obtained without proper evidence.

Commissioner Andrew Scipione became commander of the internal affairs unit in 2001, and is due to appear before the inquiry tomorrow.

Mr Barbour has maintained his giving evidence before the inquiry will jeopardise the investigation, as well as betray the confidence who spoke to him on the understanding their collaboration would remain private.

However, he said he was keep to help the inquiry to the limit of his abilities.

"I'm endeavouring to walk a very fine line here," he said.

Mr Kaldas has slammed Mr Barbour's inquiry as having focused on whistleblowers who brought Operation Mascot into the public eye, rather than focusing on improper police conduct.

"To suggest that my inquiry has focused on targeting whistleblowers is simply false," Mr Barbour said.

The ombudsman said his inquiry was focusing on whether appropriate evidence included on the warrants.

Ms Burn, who has also appeared before the inquiry, maintained she had reasonable cause to carry out the surveillance.