Australian Prime Minister Scott Morrison on Monday 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," 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."

It was after a four-year-long royal commission that prime minister offered the official apology.

The country has been shocked by revelations of the systemic and prolonged sexual assault of children in religious and government schools, institutions and sporting clubs. 

TRT World'sMelinda Nucifora has more.