The inquiry, announced by Prime Minister Colin Barnett today, following the recent jailing of Dennis John McKenna, one of the worst serial pedophile in Australia.
Questions have been raised about how McKenna is capable of sexual child abuse in Hostels St Andrew's in Katanning, where he was the Chief warden from 1975 to 1990, despite complaints to police.
Recently retired judge Peter Blaxall will head an investigation to determine how widespread the abuse and whether there may have been a cover-up that allowed to continue.
The investigation will examine allegations that complaints against the police and McKenna was fired by a senior officer in the 1970s and 80s.
McKenna was jailed for six years for sexually abusing October after six men, aged 13-15, in treatment.