NSW Deputy Police Commissioner Nick Kaldas has launched a blistering attack on NSW Ombudsman Bruce Barbour, claiming his treatment by an investigation into a long-running bugging scandal was worse than how police would be allowed to treat a criminal.

In sensational evidence to a parliamentary inquiry into Mr Barbour's two-year investigation into the bugging scandal, Mr Kaldas likened the way Mr Barbour has conducted his inquiry to the "horrors" of notorious US Senator Joseph McCarthy's pursuit of communists in the 1950s.

"We the police could not treat criminals this way and neither should we," he said.

Mr Kaldas was one of more than 100 police officers and civilians targeted by an internal police inquiry, Operation Mascot/Florida, during 1999-2001.

The operation was run by current NSW Deputy Commissioner Catherine Burn and overseen by the Special Crime and Internal Affairs unit headed by Commissioner Andrew Scipione from early 2001.

Mr Kaldas told the committee he and his family were subsequently subjected to two years of intensive surveillance, but no accusation was ever made against him. He said being targeted had caused him to miss out on promotion opportunities.

In 2003, an internal investigation, Strike Force Emblems, was launched in response to revelations that warrants issued by Supreme Court judges, authorising the bugging for Operation Mascot, included the name of a journalist and police who were never accused of wrongdoing.

Successive NSW governments have refused to release the report of Strike Force Emblems officially, although extensive details have been revealed by Fairfax Media.

The parliamentary inquiry was established last year against the wishes of the NSW government.

It was set up in response to complaints about the amount of time Mr Barbour's inquiry has taken to report and fears it was now examining the actions of whistleblowers who leaked documents relating to Mascot/Florida.

Mr Kaldas told the inquiry he was summoned to an interview with Mr Barbour on September 5 last year.

"I attended to face an onslaught, a concerted attack on my integrity and credibility," he said, adding that "an enormous amount of material was put to me and yet again my emails phone records, diary, notebooks etc were invaded and quoted to me."

"I felt that the horrors of Mascot/Florida were happening all over again," he said. "It felt to me like this was a well planned attack to silence me as one of the main complainants."

Mr Kaldas said that he had "not done anything that would justify this level of intense, intrusive targeting."

"Yet again my privacy has been utterly invaded with operation prospect where my diaries, my notebooks, my emails my phone records have all been seized by the Ombudsman and yet again the justification for this invasion of privacy is completely out of proportion to what is alleged," he told the inquiry.

"We the police could not treat criminals this way and neither should we."

Mr Kaldas told the committee he had worked in war-torn Iraq and led the international investigation into the assassination of Lebanese prime minister Rafic Hariri.

"I received many threats from Hezbollah and many other proxy groups - I fear no man," Mr Kaldas said.

He noted that he has been trusted with classified and internationally sensitive information and in Sydney "cross-examined by more QCs than I can remember in hotly contested trials".

"Yet I have never been denigrated, humiliated and had my every action and thought so unreasonably maligned as I experienced during [Mr Barbour's inquiry] Operation Prospect," Mr Kaldas said.

Mr Kaldas said he had recently watched a film, The Front, "which portrayed the horrors of the McCarthy era in the United States".

"The methodology used by the McCarthy era is very similar to that of the Ombudsman," he told the inquiry.

"No criticism will be tolerated. It will not be sufficient to admit your own sins, you must denounce friends and colleagues. The result is always preordained".

"What happened to me and my family 10 years ago was unfair and wrong - dead wrong. It's happening again now, in my view."

During his evidence, Mr Kaldas outlined how in the late 1990s and early 2000s he had  "a well known and well documented conflict with some senior officers" of SCIA, "in particular Mal Brammer, John Dolan and their team, which included Catherine Burn".

"This conflict was so deep that it should have precluded those individuals and that unit from targeting me," he argued. "It was simply too big a conflict of interest."

Mr Kaldas recounted how he was "targeted" by Mascot/Florida via covert surveillance by a corrupt former police officer codenamed M5, who tried to discuss "his misdeeds".

When Mr Kaldas "told him to go away" he was subsequently investigated over allegations that Mr Scipione - as head of internal affairs - had leaked the nature of M5's work to him. He said no such leak had occurred.

"What happened next is that I was dragged through a series of harrowing hearings and interviews by the Crime Commission and Police Integrity Commission and my career was derailed for some four years where I was denied promotion, ignoring merit, and a dark cloud hung over me," he said.

"On the other hand, Andrew Scipione, who was accused of the actual leak – arguably a far more serious allegation – was immediately promoted to Deputy Commissioner and didn't look back."

Mr Kaldas said the home of his ex-wife and children was bugged after an affidavit was sworn to the Supreme Court to obtain the warrant even though he had stopped living there "some time ago".

Mr Kaldas said his mobile and office phones were bugged and he was subjected to five or six "illegal integrity tests".

He also criticised the "ethical standards" actions of Mascot/Florida.

"One illustrative example of that is the list of codenames for us as targets where I am referred to as 'Guido' - a derogatory term for my ethnic background," he explained.

Mr Kaldas said that he has been recalled for a second interview by Mr Barbour's inquiry.

"I hold fears of his intention towards me," he said.