The AFP's Child Protection Operations Teams uncovered 500,000 images and 15,000 videos of child abuse that were shared between members of a peer-to-peer network.

Nineteen men from New South Wales, Victoria and Queensland have been arrested as a result of the year-long investigation. The latest arrest, a 24-year-old Blakehurst man, is due to face Sydney Central Local Court today. AFP Acting Deputing Commissioner of Operations, Andrew Colvin, said this operation has resulted in at least two children being removed from harmful situations.

"The videos seized as part of this operation have to be among the worst we have seen," he said. "Some depicted sexual abuse of children lasting more than two hours."

Colvin said viewing and exchanging of child abuse material will not be tolerated in Australia.

"If we are not knocking on your door this morning, then it could be tomorrow," he said.