How a young police officer brought down Australia's most notorious child cult.

The notorious apocalyptic cult known as The Family and their infamous leader Anne Hamilton-Byrne made international headlines throughout the 1980s and 1990s.

Her name and the name of the cult she led are no doubt etched in your mind forever, thanks to the many stories that came out after a teenage girl escaped and raised the alarm about what was happening in the hills above Melbourne in 1987.

Along with her husband Bill, Anne collected 28 children over the years through adoption scams, taking them from single mothers or women who had been inducted into the cult.

But for all we know about the notorious cult leader and her followers, there is one important name that has never been widely spoken in conjunction with the case. Until now.

The ABC documentary The Cult of The Family has shone a spotlight on detective Lex de Man, who did his own report on The Family in order to persuade his superiors that this it was not just a community welfare issue but a potentially a criminal one, which resulted in police setting up a task force, Operation Forest, to investigate.

In turn, police were shocked by what they found there. Children who were stolen at birth, physically abused and given mind-altering drugs such as LSD. They were all being held there as a bizarre experiment to raise a ‘master race’ of children who were supposed to save the world from Armageddon.

Now in his mid-50s, Lex de Man was a 29-year- old sergeant in the arson squad when he initially put together the report that triggered Victoria Police to set up the task force to investigate The Family.

He worked the investigation for the full five years of Operation Forest where he helped uncover details of the illegal adoptions and around Anne Hamilton Byrne’s multiple identities, her false land transfers and social security fraud that had taken place.

De Man was the only detective who worked on Operation Forest from the beginning of the operation right through to the very end. After Anne’s guilty plea, he left the force and joined the Country Fire Authority where he worked for two decades.

Since 2016 he has been CEO of Victorian Police Legacy, a caring organisation helping families of deceased police members.

An important note to take away from the documentary is that De Man has remained in close contact with many of the child survivors of the Family cult still to this day.

According to the director of The Cult of The Family, Rosie Jones, it was his unflinching drive to secure justice and his unwavering desire to see the full story told that has made the documentary possible.

"Our story is driven by Lex de Man, a charismatic detective who dedicated five years of his life to investigating The Family," she told Mamamia in a statement.  "It took me a year to gain Lex’s trust and permission to tell his side of the story. He introduced me to Adam/Roland, one of the sect children, and over three years of research, other former ‘children’, sect members and ‘insiders’ began to talk to me. What they told me was moving, shocking and profound, all at the same time.

"Their courage and resilience is inspiring and transcends this story. Lex discovered that Anne was sent to the Old Melbourne Orphanage when her father couldn’t cope with seven children and an unstable wife, who was hospitalised for 30 years as a paranoid schizophrenic.

"Stories of abuse at the Orphanage are rife. Could it be that Anne suffered there, and her experiment at Lake Eildon was in some way intended to put that right?

"There’s an urgency for this story to be told. Surviving sect members are in their 70s and 80s, and at 98, Anne lives in a suburban nursing home behind a veil of dementia."

The Cult of The Family will air on ABC on Tuesdays at 8.30pm from March 12. All three episodes will be available on ABC iview following the broadcast launch.

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