THE sister of House of Horrors mum Louise Turpin has claimed their mum let a rich paedophile sexually abuse them as kids in exchange for cash.

Louise, 49, and husband David, 56, shocked the world when police allegedly found their kids, aged between two and 29, emaciated and shackled to their beds.

As the sick pair await trial, Ms Turpin’s younger sister Teresa Robinette lifts the lid on a “dark secret” which has plagued their family for years.

In sensational new claims, Ms Robinette, 37, says she and Louise were themselves victims of systematic sexual abuse as children.

She claims their late mother, Phyllis Robinette, not only knew about the alleged abuse but also masterminded it.

Speaking exclusively to The Sun, Ms Robinette said: “Our mum should have been protecting us — but she sold us to a wealthy paedophile.

“He would slip money into my hand as he molested me. I can still feel his breath on my neck as he whispered ‘be quiet’.

“We begged her not to take us to him but she would simply say: ‘I have to clothe and feed you’. Louise was abused the worst. He destroyed my self-worth as a child and I know he destroyed hers too.”

A new Channel 5 documentary called, Tortured By Mum and Dad?The Turpin 13, explores Mrs Turpin’s dark past and poses the question — is she a victim too?

Dr Lucy McBride says: “As we know, people who are abusers tend to be people who have been abused themselves. It’s extremely said.”

Ms Robinette says: “I don’t know if Louise is a victim. She knew what she was doing was wrong. Otherwise she wouldn’t have tried to hide it.”

Investigators believe the abuse started in Texas when their parents, Louise and David Turpin, were having money problems by living beyond their means.

In 2011, the filed for bankruptcy, after falling into £360,000 ($650,000) of debt, a year after they moved into a California bungalow.

Authorities allege the evil pair choked, beat and chained the children to their beds — where they would sometimes remain for months.

They are accused of denying them access to a toilet and beating them if they washed “above the wrist”.

The children were only allowed to shower once a year.

In January 2018, the 13 were rescued after their 17-year-old daughter escaped through a small window and fled the family home.