Veda maintains a database of the credit histories of millions of Australians. Credit:Greg Newington The person they arrested, who cannot be named, was a sex deviant who was a member of an online network of child sex offenders. Taskforce Argos' arrest of him would begin a years-long investigation netting paedophiles from all over the world. "We initially arrested a Queensland offender and identified that he was a member of a network of child sex offenders," Taskforce Argos' Detective Inspector Jon Rouse said. "We assumed his identity and infiltrated the network and found there to be around 45,000 members."

Convicted sex offender Richard Huckle. The investigation initially began a process of victim identification, analysing the material shared among members of the network to find where the victims were and to pass that information on to local authorities. Then they realised the head administrator of the network was Australian. Detective Inspector Jon Rouse of Task Force Argos. Credit:Bradley Kanaris "That changed our focus," Inspector Rouse said.

"I think anyone, in the Australian way, would think that was completely unacceptable. "We ultimately identified him and sent one of our teams to South Australia to work with police there to execute an arrest warrant." That arrest warrant resulted in the arrest of Shannon McCool and officers from Taskforce Argos were able to take over his identity on the site, and from there begin the task of identifying the victim and perpetrators of contact offences against children. Thousands of leads were disseminated to law enforcement agencies around the world as members of the site were tracked down and prosecuted. Inspector Rouse doesn't know how many arrests there has been as a result of the investigation by Taskforce Argos.

"Argos disseminates thousands of leads every year nationally and internationally," he said. "We don't get operational outcomes from a lot of countries so in some instances we haven't been told what the final number is in terms of arrests and convictions." What they do know is that the key administrative members of the network were arrested because Taskforce Argos was intrinsically involved in those arrests. In at least once instance, Argos officers engaged with the offender online, live, while law enforcement agencies overseas made a stealth entry into the offender's home and arrested him. Argos closed down the website child sex offenders were using to share information, images and videos and that marked the end of what was a major operation for officers.

But it was, by no means, the end of Argos. "I would dearly love to tell you that I have put myself out of a job," he said. "The sad truth is, I have worked at Argos for 16 years and it's not going to end in the time I have left in the police service. "There is always an operation we are working on." Argos has just launched two new major operations and has another one that has been ongoing for five years.

And once again the taskforce won't be confined by borders. "The nature of the internet is there's no borders," Inspector Rouse said. "The mantra we are working on is it doesn't matter where the child is, we will investigate and disseminate that information." And that means the officers will continue tracking down some of the vilest offenders in the world. "I think there is a perception ... that it's horrendous work," Inspector Rouse said.

"The reality is all of the investigators here, including myself, the way we view the videos and images we are involved in is as evidence of a crime. "We find the work rewarding because we are stopping contact sexual abuse in its track." Like much police work, what Argos officers see is unpleasant but it is a part of the job that results in criminals being put behind bars. "This is no different, for me anyway, from our road traffic police dealing with horrendous trauma on the roads or our homicide detectives who see some horrific things," Inspector Rouse said. "Policing by its nature has trauma. If we are involved it is generally not good news.

"This is just one microcosm of policing that we do and we are very conscious of the well being of our staff."