Most heinous child sex offender taught at Latrobe Valley schools
By AIDAN KNIGHT
WARNING: The content of this story is extremely distressing.
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A FORMER physical education teacher from the Latrobe Valley has been revealed to be the identity of Australia’s worst child sex offender in history.
For a decade, a suppression order prevented media from publishing anything identifying the individual, who is currently serving the lengthiest jail sentence ever delivered for child sex crimes in the country.
William Gilfillan’s criminal record dates back to 1984, when the Victorian Education Department investigated three reports of abuse from female students at Traralgon High School, where he taught until the subsequent controversy saw him moved to Presentation College, Moe – an all-girls school.
All three of these students reported to both school captains and the principal at the time that Gilfillan had graphically violated them in acts that involved the use of caliper measuring instruments, which were used by PE teachers at the time to ‘measure body fat’. The details of the crimes are not fit for publishing, such is their disturbing nature.
Gilfillan (68), who preferred to go by Rob (an abbreviation of his middle name, Robert), was then accused of penetrating a fourth female student at his new position shortly after his transfer.
Neither time was he fired, nor were Victorian Police contacted by the education department, who only ever opted to conduct their own independent investigations.
This is alarmingly similar to the case of Peter Farmer and his victims (as reported in the Express, November 5, 2025), which also occurred at a school in Moe.
Instead, the offender left the country and found refuge in Nauru for some time. When he eventually did return to Australia, he did not set foot in Victoria, instead choosing to teach at girls schools in New South Wales and Queensland, and also juggled a research project for Southern Cross University at the same time.
In 2011, police were finally involved when even more victims brought forward further allegations – again the same as those recorded in the 1980’s.
Gilfillan absconded a second time, and lived in Papua New Guinea for two years before he was extracted by the PNG government, on extradition of charges laid back home in Australia.
These were, of course, offences of sexual acts towards and against children, totalling a staggering 126 charges. To date, only 82 of those have been processed, upon which the legality of his public identity was hinged. Of those charges, 78 have been found guilty.
More than 70 of the total took place outside Victoria, and one of the charges related to his abuse of a five-year-old girl – highlighting the
range of predatory behaviour Gilfillan engaged in.
Every single charge was denied by the accused, who claims that students were driven by “infatuation turned to jealousy” to “plot to take him down”, as described by his defence of the allegations of 1984. He also claimed under oath that one of the alleged victims contacted him to confess such a ploy, over the phone. He claimed she said “she was struggling with her studies and it was an opportunity to get to do her dream and go to university”.
Gilfillan told the jury deciding the case he had a witness to this phone call – who turned out to also be an already convicted child sex offender,
The Express was able to connect Gilfillan as the (previously anonymous) offending father reported in the true crime podcast Shadow of a Doubt, which was investigated and produced by The Australian in 2023.
The specifics of the podcast, released while the suppression orders on Gilfillan’s identity were still in place, saw dismissed appeals by the NSW justice system by two parents – referred to in the judgment as WG and KG – who had been convicted of extensive historical child sexual offences committed against their own daughter. Court documents regarding this appeal are dated September 2019.
It is likely that more information will come to light as further charges are processed, allowing a greater understanding of the horrific events perpetrated and how they were able to continue for so long.
This connection was also confirmed to the Express by a former Traralgon High School student who thankfully, was not made a target of predatory behaviour during their shared time at the school in the 80’s. The source, who shall remain anonymous, was not privy to any explicit wrongdoing, but further corroborated Gilfillan’s persona of being “a great guy”, which was evidently used to mask his depravity.
“I suspect other teachers must have known something – he was thick as thieves with one other male teacher in particular (I am not alleging any wrongdoing on the part of the other teacher, but others MUST have suspected)”, the former student told the Express.
Once confirmed as the father detailed by The Australian, the Express can now confirm some of his guilty charges relate directly to the 14 year abuse of his daughter, which members of the jury described as the worst case of child abuse they had ever been made aware of.
The 12-week trial at Sydney Downing Centre District Court, with details again much too distressing to print, involved the imprisonment of Gilfillan’s daughter in a shed and chicken coop, where she would lay tied up for
days at a time without food, absent from school.
This occurred from the age of five, and progressed to acts involving barbed wire and being locked inside a sporting goods trunk as she grew older. These days in the shed began to be used as a form of punishment, especially if she was not found to be excelling in sporting competitions.
The mother, only known to the public as KG, was complicit in these acts, and even offered their daughter ‘tips’ on how to better please her father, and once told her (according to the court) “Dad has his reasons why he does these things.”
Years later, Gilfillan abused her as a direct punishment for telling a counsellor about his abuse. This led to her approaching police in 2011, where charges were not only laid but also an AVO was placed against both parents to protect her from her parents in the interim, following stalking and public abuse in carparks.
When the pair were arrested, police raided their Sydney home, finding a year’s-old evidence, and the pair were sentenced in late 2016.
Survivors of Gilfillan’s abuse were legally barred from speaking publicly about their experiences while his remaining charges were before the courts.
One woman, identified only as ‘Jaye’ for this publication, described the effect of these suppression laws as “dehumanising,” saying being unable to tell her story made her feel “invisible and powerless again.” She has since become a lawyer and argued Victorian evidence laws should better balance fair trial protections with survivors’ rights to tell their own stories once prosecutions are complete.
Gilfillan is serving a current sentence of 48 years, with additional time handed down in Victorian courts in April, as the sentencing for his unheard-of amount of atrocities continues. This current sentence carries a non-parole period of 36 years for his offences, which spanned decades and jurisdictions.
Findings of the Royal Commission into Institutional Responses to Child Sexual Abuse (2014-2017) confirmed that education departments across Australia routinely dealt with abuse complaints as internal employment matters, often opting to transfer staff rather than dismiss or report them. The commission found this practice prioritised institutional reputation over child safety and allowed known or suspected offenders to continue working with children, sometimes across multiple jurisdictions.
In Gilfillan’s case, that lack of mandatory reporting and external oversight meant he was able to leave Victoria and continue teaching interstate, a failure of systems that would only be addressed decades later through reforms to reporting laws, child safety standards and teacher registration powers.
The reforms that now compel reporting, empower regulators and criminalise silence were born from cases like Gilfillan’s, but for his victims, they arrived decades too late.
