Seven percent of priests in Australia's Catholic Church were accused of sexually abusing children over the past several decades, a lawyer said on Monday as officials investigating institutional abuse across Australia revealed for the first time the extent of the crisis.

The statistics were released during the opening address of a hearing of Australia's Royal Commission into Institutional Responses to Child Sexual Abuse. The royal commission - which is Australia's highest form of inquiry - has been investigating since 2013 how the Catholic Church and other institutions responded to the sexual abuse of children over decades.