Deputy police commissioner Nick Kaldas has launched a fresh attack on former NSW ombudsman Bruce Barbour over his investigation of a police bugging scandal, declaring he has demonstrated bias and has "tainted" the office.

In a submission to a parliamentary inquiry published on Wednesday, Arthur Moses, SC, on behalf of Mr Kaldas, argues Mr Barbour's investigation, Operation Prospect – which has already run for more than two years – is "invalidated and must be held again afresh."

Fomer ombudsman Bruce Barbour. His acting replacement says the attack is 'without merit'. Credit:Dallas Kilponen

The submission says Mr Barbour's actions in referring Mr Kaldas to the Director of Public Prosecutions for potential criminal charges have been "possibly unlawful" and potentially defamatory of Mr Kaldas.

It accuses Mr Barbour of making the referral in retaliation for the establishment of the parliamentary inquiry to examine the conduct of his own investigation.