Police chief has my support: Baird

NSW Premier Mike Baird says revelations from the police bugging scandal haven't undermined his confidence in Police Commissioner Andrew Scipione.

"Andrew Scipione still does have my support," he told reporters on Thursday.

Mr Scipione appeared before a parliamentary inquiry on Wednesday where he defended his involvement in an internal police surveillance operation more than 10 years ago and subsequent investigations.

Mr Scipione, who headed the Special Crime and Internal Affairs unit (SCIA) for part of 2001, told the inquiry he received complaints about the unit's activities that year and immediately acted, taking the issue to the then deputy commissioner.

He also denied having put the controversial matter in the "too hard basket" when he took the state's top policing job in 2007, claiming he was told two years earlier the matter had been finalised.

Mr Baird said he was concerned by a number of revelations from the inquiry but said the government would defer any action until all the facts were known.

He defended Mr Scipione, describing his performance as commissioner as "outstanding".

"Police are doing an excellent job, notwithstanding some of the concerns being raised (by the inquiry)," he said.

The anti-corruption surveillance operation in question, dubbed Mascot, targeted more than 100 officers between 1999 and 2001.

It's been a festering wound within the force ever since, with allegations some affidavits used to get the bugging warrants included false information and there was an intent to undermine rivals.

The state ombudsman has been investigating for more than two years and plans to release a full report later in the year.

Mr Scipione said he had instructed his police to give everything they had to the ombudsman's inquiry.