In 2014, detectives from a specialist Queensland police unit came across a small number of videos and images posted online, depicting the abuse of two girls but containing few clues as to where in the world they had been made.
After the discovery by taskforce Argos, the Australian Federal Police (AFP) and other agencies began an international search for the victims.
This included uploading the material to a database that could be searched by other law enforcement agencies.
But the trail soon went cold. Whoever made the images was not a prolific poster on the dark web, and was never considered among the “most wanted” targets of child abuse investigators.
Almost a decade later, in August 2022, the AFP made a breakthrough in the case while re-examining the images uncovered by Argos in 2014.
Guardian Australia understands detectives sought to identify bedsheets depicted in the background of one of the images and were eventually able to trace them to a childcare centre in suburban Brisbane.
Remarkably, after a global investigation, the images and videos had been made less than 20km away from the Argos office.
Perhaps more remarkably, the tiny traces from those few videos and images ultimately led to the discovery of a childcare worker now accused of being Australia’s worst serial paedophile.
On Tuesday the AFP and Queensland police announced the man, aged 45, had been charged with 1,623 child abuse offences against 91 girls, including 136 counts of rape and 11o counts of sexual intercourse with a child under 10.
The AFP’s assistant commissioner, Justine Gough, described the alleged offence as “unfathomable”.
“Given there were so many alleged images and videos of children recorded over 15 years on the alleged offender’s devices, the process of identification took time, skill and determination,” Gough said.
“While I am extremely proud of law enforcement’s persistence, and their unwavering dedication to identify this alleged offender and stop further abuse, this is chilling news.”
On 20 October last year, police raided the Gold Coast house of a man who worked at the Brisbane childcare centre from 2007 to 2013.
Inside the house police allegedly found cameras and phones containing almost 4,000 child abuse images and videos dating back to 2007.
Sources familiar with the investigation say the discovery stunned police. “They found a needle in a haystack and then a stack of needles,” the source said.
What followed was a painstaking process, over 10 months, to track the man’s movements and identify alleged victims.
The AFP said the man “recorded his offending on phones and cameras” while working at childcare centres in Brisbane from 2007 to 2013, in Sydney from 2014 to 2017, and in Brisbane from 2018 to 2022. He is also alleged to have made child abuse material while working overseas, understood to be in Italy, in 2013 and 2014.
Police identified 87 Australian girls, all aged under 10, from the material.
“The AFP is also highly-confident that all 87 Australian children who were recorded in the alleged child abuse material have been identified,” the AFP statement said.
“The parents of all the Australian children recorded in the alleged child abuse material have been informed of the investigation. Some of the individuals identified in the alleged child abuse material are now aged over 18 years and have been informed. Support services have been offered and continue to be provided.
The AFP said the man worked at other childcare centres but the police force is “highly confident the man did not allegedly offend at those centres”.
Argos is tasked with investigating online child exploitation material. The unit’s takeover of a child abuse website by detectives in 2014 and subsequent investigations have snared some of the world’s most notorious serial child abusers.
