The Archbishop of Dublin has written a scathing letter in response to the child abuse scandal rocking the Roman Catholic Church in Ireland.

"The church has failed people. The church has failed children," Diarmuid Martin said in a column published in the Irish Times on Monday.

"There is no denying that."

The column is the harshest criticism by a Catholic leader since investigators last week documented widespread abuse of children in schools run by 18 Catholic orders.

Last week, High Court Justice Sean Ryan wrote the 2,600-page final report of Ireland's Commission to Inquire Into Child Abuse. The report is based on testimony from 30,000 former students who were sent to Ireland's austere network of industrial schools, reformatories, orphanages and hostels from the 1930s until the last church-run facilities were shut in the 1990s.

The report found molestation and rape were "endemic" in boys' facilities, chiefly run by the Christian Brothers order.

In the column, the archbishop said the church has lost credibility because of its weak response to abuse revelations.

He accuses the leaders of the orders of living in denial about members behaving "with practically no morals.

"The first thing the church has to do is to move out of any mode of denial," he wrote.

"That was the position for far too long and it is still there."

With files from The Associated Press