CANBERRA (AFP) - Australian Prime Minister Scott Morrison on Monday (Oct 22) issued an emotive apology to children who suffered sexual abuse, saying the state had failed to protect them from "evil dark" crimes committed over decades.

"This was done by Australians to Australians, enemies in our midst, enemies in our midst," Mr Morrison told a parliamentary chamber in a televised speech, his voice trembling with emotion.

"As a nation, we failed them, we forsook them, and that will always be our shame."