Outgoing NSW Ombudsman Bruce Barbour has rejected a call for a single watchdog to oversee NSW police following a long-running bugging scandal, warning it could reduce public confidence in the force.

Mr Barbour has also dismissed the benefits of a single police oversight agency as "largely illusory", in a rebuke to a parliamentary committee that recommended the move.

Bruce Barbour: "No cogent evidence that the current system is failing." Credit:Dallas Kilponen

The state government has commissioned former Liberal opposition attorney-general Andrew Tink to review the possibility of the creation of a single police oversight agency in NSW.

It will include consideration of whether the British Independent Police Complaints Commission is a suitable model for NSW.