A New South Wales inquiry has heard that a victim of child sexual abuse by a Hunter Valley Catholic priest made a complaint about how she was treated by a investigating police officer.

The Special Commission in Newcastle is investigating Detective Inspector Peter Fox's claims the Maitland-Newcaslte Catholic Diocese and NSW Police covered up allegations of child sexual abuse by two priests.

Brad Tayler, a former Newcastle crime manager is giving evidence at the public hearings.

The court has heard a witness was hassled to give her statement and later complained about the investigating officer.

Peter Fox's barrister Mark Cohen told the court the victim was distressed and asked Mr Tayler what he did to help her.

Mr Tayler rejected claims there was a conflict of interest in him investigating the complaint as the Strike Force Lantle manager.

He said its rubbish that he was trying to avoid an embarrassing situation for police.

The man dubbed one of Australia's best sex crimes investigators is expected to front the inquiry later today.

Detective Inspector Paul Jacob was assigned to help local detectives investigating the matter.

Former policeman, now solicitor, Justin Quinn is also expected to give evidence.