Australian police announced Tuesday the dismantling of a "sophisticated" child abuse ring, saying 19 men had been arrested with the help of the FBI.

Federal Police Commander Helen Schneider said 13 children had been rescued from the clutches of the "dangerous" network, which shared encrypted child abuse material on the dark web.

"The lengths this network went through to avoid detection are an indication of just how dangerous they were," she told reporters.

The ring was busted as part of a larger cross-border investigation run by the FBI, which has already charged 79 alleged offenders in the United States.

The long-running investigation captured headlines in 2021, when FBI special agents Daniel Alfin and Laura Schwartzenberger were shot and killed while searching a Florida apartment.

A number of the Australian men were professionals who worked with computers for a living, police said.