Videos and photos of schoolchildren taken by a Goldfields teacher remained on the internet for six months after the man was charged over links to an international child abuse ring.
The primary school teacher, who has pleaded guilty to more than 100 charges of crimes against children, posted dozens of videos and images of his students on YouTube and a personal blog up until days before his arrest in June last year.
He was arrested as part of Operation Thunderer, the Australian arm of an international investigation targeting an alleged global paedophile network that shared videos of children being sexually abused.
The man was one of six WA men identified by Canadian authorities as buying photographs and videos from a Canadian man who created and sold child exploitation material.
When police raided his Goldfields home and checked his computer, they not only found images of naked children he had bought but also more than 50 videos he had made of himself groping students at two rural WA primary schools where he had worked.
Separate to the videos the police uncovered, the teacher also maintained a YouTube channel and personal blog with names, images and videos of dozens of his students.
The sites, and the images of the children, remained online since his arrest and were removed only after The West Australian contacted police about their existence.
Although there were no alleged crimes portrayed in the videos or images publicly posted on the two sites, police alerted WA Education Department officials, who asked that the webpages, which clearly identified many of his students, be taken down.
The department's director of standards and integrity, Mike Cullen, said the department had worked with affected students and teachers to offer support in a discreet manner in close collaboration with police.
He said the teacher's behaviour was "criminal and absolutely deplorable".
"Unfortunately, no matter how many checks are in place it is nearly impossible to detect beforehand deviant individuals who have no recorded history of offences against children," Mr Cullen said.
He said the department had significant criminal record screening processes.
All teachers were required to have a current Working With Children Card and there was a team of investigators who examined allegations of staff misconduct and worked closely with WA Police, he said.
Mr Cullen said that as soon as the department was made aware of the allegations, it sacked the teacher and served him with a section 240 order banning him from any school or department site where children were involved.
The teacher has pleaded guilty to all charges and will be sentenced later this month on 54 counts of indecently dealing with a child under 13, 47 counts of indecently recording a child under 13 and two counts of possessing child exploitation material.
The maximum penalty for each of the indecent dealing and indecent recording charges is 10 years.