The man, identified only as CFW, works with jobseekers aged 17 years and over, however he had been prevented from being assigned any 17-year-olds prior to this decision.
He was charged in 2005 with knowingly possessing child pornography after allegedly downloading prohibited material from various websites between 2002 and 2004.
It went to court in 2006, where the magistrate described the man's actions as "very suspicious" however he was not convicted because prosecutors could not prove beyond reasonable doubt the possibility that he may have accidentally saved the images while he was downloading adult pornography.
This was enough for the Children's Guardian to deny him a Working with Children Check clearance, however after a lengthy legal battle that went all the way to the Supreme Court and back, the Civil and Administrative Tribunal has now cleared him to work with teenagers.
The man said he visited file-sharing websites instead of regular adult porn websites because he preferred amateur porn that was more "real" than the "glammed and made-up" images on professional websites.
"He also asserted that he encountered child pornography images on the computer when looking for information about conspiracy theories on 'shared websites' and that at the time he was socialising with people with similar interests and using a lot of cannabis," the tribunal said.
"The applicant expressed embarrassment about his then interests in theories such as 'crop circles' and UFOs and stated that he has a tattoo that he would now like to have removed."
The tribunal did not say what the tattoo depicted.
Incredibly, the tribunal acknowledged there was a "lingering doubt or suspicion" that the man had knowingly downloaded the child porn but said "we are satisfied that he does not pose a real and appreciable risk to children".
It cited evidence from a forensic psychologist that he did not have a "pedophilic disorder" and even if it was assumed he had deliberately downloaded child pornography he was "managing the risk factors".
It was noted that his period of indulging in adult porn and heavy use of cannabis and alcohol followed the death of his girlfriend in a car accident, and that he had been a good citizen, community volunteer and stepfather since then.
"Even if he did knowingly download child pornography 12 to 14 years ago, since then he has an almost unblemished record," the tribunal said.
"He has sought assistance in relation to his mental health; he has significantly changed his lifestyle; and has been assessed by a forensic psychologist who is an expert in the area as not presenting a risk to children, even if he did commit the offence."
Criminologist Carol Ronken from the child protection group Bravehearts said the case was proof that working with children bans couldn't be relied upon to screen out all potentially risky individuals.
"The right to appeal should be protected, however cases like this one remind us that organisations that work with children need to have strong child protection and risk management policies in place," she told news.com.au.
"We often don't know what the risks are, and although we don't want to see organisations treating every one with suspicion, it is about ensuring that policies and systems are in place to ensure a child-safe environment."
Another child protection source said the decision was ironic, given that the whole point of a Working with Children Clearance was to identify all potential risks, not just official convictions.
"The purpose of a WWCC is to identify previous incidents that indicate a person could pose a potential risk to children, which may not come up in a police check," said the insider.
"It is a very important issue that you're raising."
The Children's Guardian has already appealed a previous tribunal decision on the case to the Supreme Court, which referred it back to a reconstituted tribunal for a new ruling.
The Children's Guardian told news.com.au it was now seeking advice to see if there was a legal error upon which it could appeal again.