CANBERRA — Australian Prime Minister Scott Morrison issued a national apology to victims of child sex abuse in an emotional address to parliament on Monday, acknowledging the state failed to stop "evil dark crimes" committed over decades.

"This was done by Australians to Australians, enemies in our midst, enemies in our midst," Morrison told parliament in a nationally televised address.

"As a nation, we failed them, we forsook them, and that will always be our shame," he said, his voice cracking as he recounted abuse that permeated religious and state-backed institutions.

Decrying abuse that happened "day after day, week after week, month after month, year after year, decade after decade" in schools, churches, youth groups, scout groups, orphanages, sports clubs and family homes, Morrison declared a new national credo in the face of allegations: "We believe you."

"Today, we say sorry, to the children we failed. Sorry. To the parents whose trust was betrayed and who have struggled to pick up the pieces. Sorry. To the whistleblowers, who we did not listen to. Sorry.

"To the spouses, partners, wives, husbands, children, who have dealt with the consequences of the abuse, cover-ups and obstruction. Sorry. To generations past and present. Sorry."

The state apology comes after a five-year Royal Commission that detailed more than 15,000 survivors’ harrowing child sex abuse claims involving thousands of institutions.

In parliament, lawmakers stood for a moment of silence following the remarks as hundreds of survivors looked on or watched in official events across the country.

Relatives of victims who have died wore the tags with the names of daughters and sons, brothers and sisters, for whom this apology comes too late.

A series of institutions have already apologised for their failings, including Australian Catholic leaders who have lamented the church’s "shameful" history of child abuse and cover-ups.

According to the Royal Commission, seven percent of Catholic priests in Australia were accused of abuse between 1950 and 2010, but the allegations were never investigated, with children ignored and even punished.

Some senior members of the church in Australia have been prosecuted and found guilty of covering up abuse. — AFP