The state government tasked the Ombudsman in October 2012 with inquiring into allegations surrounding illegal bugging by the NSW Police's Special Crime and Internal Affairs and the NSW Crime Commission between 1999 and 2001 and the investigation that followed into it.

But after more than two years, the $3 million inquiry, dubbed Operation Prospect and held behind closed doors, has released no specific details.

Now, The Shooters and Fishers Party, with the support of Labor and The Greens, will establish an inquiry that will examine the bugging allegations, the subsequent police investigation into those allegations and the Ombudsman's inquiry. It will report by February 2015.

Shadow attorney-general Paul Lynch said Labor was in support of the inquiry because the original matters involving allegations of police bugging "were extremely serious".

"It's taken way too long to get to this stage," he said. "These things will undoubtedly benefit from ventilation in public".

The Greens justice spokesman David Shoebridge said the inquiry would remove the secrecy behind the police bugging scandal which has affected the most senior ranks of the NSW Police.

The current Commissioner, Andrew Scipione, and a current Deputy Commissioner, Catherine Burn, worked at SCIA at relevant times. One of the detectives SCIA was bugging was Nick Kaldas, now also a Deputy Commissioner.

"What we have is a secret police investigation that obtained secret warrants, that was then reviewed by a secret police investigation and is now being considered by a seemingly endless secret Ombudsman's inquiry," Mr Shoebridge said. "This secrecy must stop."

Between 1999 and 2001, the  SCIA and the crime commission ran a covert investigation codenamed Operation Mascot into allegedly corrupt NSW police.

Central to Mascot was a serving NSW police officer, codenamed M5, who went to work for SCIA and the commission, wearing a wire to bug his colleagues, some of whom were undoubtedly corrupt. But many of those he sought to entrap were honest police.

Some listening device warrants obtained by SCIA and the commission contained more than 100 names, mainly of former and serving police.

In many cases, the affidavits presented to Supreme Court judges contained no information whatsoever that would justify the bugging, and Fairfax Media has established that some of the information in the affidavits was false.

Many police involved in the case believe numerous criminal offences have been committed by some officers of the SCIA and the commission.

Complaints by police, including some from within SCIA itself, were internally investigated by NSW police from Strike Force Emblems as far back as 2004. But inquiries were stymied by the secrecy provisions of the NSW Crime Commission, which refused to co-operate or hand over crucial documents.

Successive governments refused to release the Emblems reports – but they were obtained by Fairfax Media. The reports said "criminal conduct" and revenge might have been behind the mass bugging.

The first Emblems report found there may have been "criminal conduct" involved in the bugging of 100 serving and former police.

Even M5, the NSW police officer doing the undercover bugging, confessed that in some cases he was "settling old scores" and "assisting, nurturing corruption".