It was the sexual abuse case labelled the “worst of the worst”. Late last month, an Australian father and mother were found guilty of dozens of child sex offences against their daughter over a 14-year period.

The abuse began when the victim was five years old and continued into her late teens. Her father often forced her to sleep in an old shed where she was raped, tortured and denied food, with the knowledge and complicity of her mother. While competing at a national level in athletics, her abuse went unnoticed outside her family.

After leaving home at 18, she was able to disclose her lifelong abuse to detectives despite her parents’ ongoing efforts to stalk and assault her. The subsequent investigation uncovered the indecent assault of her sister. A sentencing hearing for their parents will be held in September.

The sheer scope of the abuse visited upon this woman is shocking. It is tempting to view her case as an aberration. However, it is just one of a number of egregious incest cases reported in Australia in recent years.

On the rise?

In 2008, a Victorian teenager killed her stepfather to bring years of sadistic sexual abuse to an end. This included the mass production of child abuse images.

A school friend said she told a school counsellor that she suspected the girl was being abused. Another friend said a teacher raised concerns about the stepfather with her. No report was made to the state government under mandatory reporting laws.

In 2009, it was revealed that a Victorian woman had been sexually assaulted and controlled by her father for 30 years. She gave birth to four children by him.

The abuse continued despite the active involvement of social services in the family. The woman said she had contact with 22 social workers and disclosed her abuse to authorities, but no action was taken.

In 2012, New South Wales authorities raided the rural compound of an extended family where incest had been endemic for generations. The family had eluded detection by child protection services for decades.

It took seven “risk of significant harm” reports before the 12 children on the property were taken into care.

How the abuse can be missed

In each of these cases, there were systemic failures to detect incest or protect victims. The unresponsiveness of relevant institutions and services enabled the abuse to continue for years or decades under the noses of authorities.

Without intervention, incest can escalate to the point where some children live in states of sexual captivity that persist well into adulthood.

A study published in 2012 of ten Australian women reporting prolonged incest by their father into adulthood found the mean duration of incestuous abuse was 31 years. The estimated average number of sexual abuse episodes was more than 3,300 in the lifetime of each woman.

It was common for the women to describe abuse by other relatives and the father’s “friends” as well. Sexual abuse was interwoven with extreme violence and the women reported being locked in rooms and kennels as children.

This research is corroborated by my study of Australian adults reporting organised abuse in childhood. For most of my interviewees, incestuous fathers orchestrated their abuse. It continued into adulthood for some.

I continue to hear from women who describe incestuous abuse that is virtually identical to the “worst of the worst” cases. These women remain overwhelmingly afraid of their violent fathers and the consequences of approaching authorities. They struggle to find mental health care for their trauma-related and dissociative psychological symptoms. This leaves them economically and socially marginalised, and vulnerable to victimisation.

Their fragile mental health is a major obstacle to providing a statement to police or withstanding an adversarial court process.

Those incest perpetrators who integrate the internet and digital technology into their offending are potentially more vulnerable to prosecution.

For instance, this year, a Perth father was jailed for 22 years for sexually abusing his daughter and for making contact with other men online who he enabled to abuse her as well. His online advertisements offering his “young daughter” for “modelling” jobs, and the child abuse material that he manufactured, provided strong evidence of guilt.

Most incest perpetrators are not so visible, or so sloppy. They are usually obsessed with power and control and strictly regulate family life to minimise the likelihood of detection.

Some incest offenders retain strong community and business ties that effectively inoculate them from suspicion. A family that is not showing overt signs of dysfunction is unlikely to attract the attention of child protection authorities. Under these conditions, the family becomes the perfect staging ground for sexual exploitation.

The once-taboo topics of domestic violence and institutional abuse are now front-page news, but repeated reports of incest have not registered in public awareness as evidence of a serious problem. The last broad-based public inquiry to consider incest finished in the late 1980s, well before the full extent of incest in Australia had become apparent.

Since then, the underlying factors that make incest possible have gone largely unexamined. Even the “worst” cases attract only a flurry of attention before fading from view.

Until the invisibility of incest is tackled, the “worst of the worst” is not just a possibility in Australia. For some children and women, it is their inescapable reality.

If this article has raised any issues for you, please contact 1800 RESPECT through their toll-free national counselling hotline or online. You can also find support through Lifeline on 13 11 14. The Blue Knot Foundation provides telephone counselling for survivors of childhood trauma on 1300 657 380.