Representatives for whistleblower Detective Chief Inspector Fox, Newcastle Herald journalist Joanne McCarthy, NSW Police Commissioner Andrew Scipione and several Catholic Church clergy members are expected to read submissions during the final three hearing days.

NSW Premier Barry O'Farrell established the commission of inquiry, the first of its kind in Australia, after Mr Fox's open letter to the Premier was published in the Herald in November last year and after he appeared on the ABC's Lateline.

The inquiry, which ran between May and August this year, has considered police investigations of the late Hunter paedophile priests Denis McAlinden and Jim Fletcher and examined the Church's handling of allegations involving the priests.

Mr Fox alleged the Church failed to report child sex allegations to police, failed to co-operate with police and alerted alleged offenders.

Prime minister at the time Julia Gillard announced a federal royal commission days after Mr O'Farrell's decision.

The hearing, before Commissioner Margaret Cunneen SC, is expected to continue through to Wednesday.