The joint investigation began after two FBI agents investigating the alleged pedophile ring were fatally shot in 2021 while executing a search warrant in Sunrise, Florida, for a man suspected of being in possession of child abuse material, the AFP noted in a news release.

Special Agents Daniel Alfin and Laura Schwartzenberger were fatally shot, while the gunman, David Lee Huber, 55, was also killed, NBC News previously reported.

The AFP said the coordinated probe was formally launched in 2022 after the FBI provided the AFP-led Australian Centre to Counter Child Exploitation with intelligence about Australian individuals suspected of being part of a "peer-to-peer network allegedly sharing child abuse material on the dark web."

The Australian suspects are between the ages of 32 to 81 years old, the AFP said. So far, two have been sentenced, it said.

Most of the Australian suspects were employed in occupations that required a high degree of knowledge on internet networks, the AFP said.

"Members used software to anonymously share files, chat on message boards and access websites within the network," it said.

Some were also accused of having produced their own child abuse material to share with members of the network, the AFP said.

“Viewing, distributing or producing child abuse material is a horrific crime, and the lengths that these alleged offenders went to in order to avoid detection makes them especially dangerous — the longer they avoid detection the longer they can perpetuate the cycle of abuse," AFP Commander Helen Schneider said in a statement.

“The success of Operation Bakis demonstrates the importance of partnerships for law enforcement, at a national level here in Australia, but also at an international level," she said.

“We are proud of our longstanding relationship with the Australian Federal Police resulting in 19 Australian men facing criminal prosecution as a result of our collaborative investigation," FBI Legal Attaché Nitiana Mann said in a separate statement.

“The complexity and anonymity of these platforms means that no agency or country can fight these threats alone," Mann said. “As we continue to build bridges through collaboration and teamwork, we can ensure the good guys win and the bad guys lose.”

Mann said that 43 people had been convicted of child abuse offenses in the U.S. as part of the investigation, according to the Associated Press.

The FBI had also alerted other countries to suspects within their jurisdictions, Mann said according to the AP, but did not name those countries.