The Australian arm of an elaborate online child abuse network has been uncovered after the murder of two FBI agents revealed an international investigation targeting child abuse material on the dark web.

FBI agents Daniel Alfin and Laura Schwartzenberger were fatally shot by a pedophile computer programmer while they served a search warrant on his Florida home in 2021.

The reclusive IT worker, 55-year-old David Lee Huber, was part of a sophisticated global child abuse network, but killed himself before charges were able to be laid.

An FBI-led international operation was later set up to target offenders on the platform, including Australian members sharing and creating child abuse material on the dark web network.

Operation Bakis, led by the Australian Federal Police’s anti-child exploitation centre, ultimately charged 19 men with child abuse offences and removed 13 children from harm.

Two Australian offenders have since been sentenced, while others remain before the courts.

The men, aged between 32 and 81, were operating across all Australian states and territories.

Most were employed in occupations that required a “high degree” of knowledge about information and communications technology, the AFP said.

“Members used software to anonymously share files, chat on message boards and access websites within the network,” the force said in a statement on Tuesday.

“Network members were able to search for and distribute images and videos of child abuse material and allegedly used encryption and other methods to avoid law enforcement detection.”

AFP Commander Helen Schneider said criminals using encryption and the dark web are a challenge for law enforcement.

“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,” Ms Schneider said.

The related FBI investigation has led to 79 people being arrested for their alleged involvement in the network.

– AAP