Australia's Roman Catholic Church has confirmed that 620 children have been sexually abused by its priests since the 1930s in the state of Victoria, the ABC reported on Sunday.

The Catholic Church of Victoria's admission came in a submission to a state parliamentary inquiry into the handling of child abuse cases by religious and other organizations after the suicides of dozens of people abused by clergy.

Campaigners, however, say the real figure could be up to 10,000 victims in the state of Victoria alone.

Most of the abuse cases took place between the 1960s and the 1980s, with another 45 cases being investigated.

In the submission, the Catholic Church said it committed to fully cooperate with the inquiry and to not "disguising, diminishing or avoiding the actions of those who have betrayed a sacred trust".

Father Shane Mackinlay of the Ballarat Diocese admitted the church had its "head in the sand" for a long time, adding there had been a history of resistance to face the truth about "shocking abuse" that happened within the church, both by the clergy and in the wider community.

Child abuse by Roman Catholic priests has been a top issue in Australia in recent years. During his visit to Australia in July 2008, Pope Benedict XVI made a public apology for the abuse.