The world was left shocked when news broke of the Turpin family torture.

How could a mother and father living in a quiet suburban street abuse their 13 children for over a decade without anyone noticing?

Tonight on 60 Minutes, reporter Liam Bartlett goes inside the depraved world of David and Louise Turpin.

Speaking to those closest to the sadistic parents, he uncovers an evil family legacy that leads back to three house of horrors – all disguised as happy suburban homes.

Visiting each home, 60 Minutes is granted an insight into what may have led to – and prevented - one of America’s worst cases of child abuse.

On January 14, a teenage girl called emergency services claiming to have escaped from her house in Perris, California.

The 17-year-old said she and her 12 siblings had been held captive and subjected to repeated abuse, torture and starvation at the hands of their parents.

When police arrived at the scene they found children chained to their beds in a torture chamber covered in human faeces.

The children were starved to near skin and bone, severely malnourished and mentally undeveloped.

As Bartlett reports tonight, the horrific truth of what really went on in the Turpin family home can be traced back to a dark family secret that turned Louise Turpin into a cruel, sadistic psychopath.

“(Louise) took exactly what we went through and intensified it by like a hundred for those kids,” Louise Turpin’s sister Teresa Robinette told 60 Minutes.

Along with Louise’s younger brother, Billy Lambert, Ms Robinette takes 60 Minutes back to their original family home in Princeton – what she describes as the original house of horrors.

Sixteen-year-old Louise escaped Princeton with her older boyfriend, David, and moved to Texas.

They began to expand their new family and in the span of 15 years they had eight children.

Ricky and Shelly Vinyard spent a decade living across the gravel road from David and Louise in Rio Vista.

Their two young daughters would play with the Turpin children until the Vineyards discovered “there was something disturbing” about their neighbours.

What they reveal to Bartlett was the first real warning sign of the parents’ abuse.

By the time the Turpin family left Texas in 2010, they had added another four children to their ever-growing brood.

Their curious neighbours decided to walk through the abandoned house.

They tell Bartlett it is an experience they’ll never be able to erase from their memory.

“It was a house of horrors. A true house of horrors. It was right up under our nose and we didn’t see it.”

Despite their horrific discovery, the Vinyards never alerted authorities, and so David and Louise Turpin went on to not only have another child but continue to escalate their abuse in Perris, south California.

As Bartlett reports, of all the neighbours that encountered the Turpins, no-one ever reported their bizarre behaviour.

Their most recent neighbours in fact denied any knowledge of the unfathomable conditions the children were living in, despite claiming they saw two of the older boys digging through the rubbish to find food at night.

“What makes this case even more shameful is it could have – and should have – all been avoided,” Bartlett said.