A vile child abuser who waterboarded a 6-year-old girl and made her run on a treadmill for more than four hours in his torture house has been jailed for 12 years.

Garth Gatland, of Cambridge, England, also force-fed the girl and told her to hold a wooden spoon in her teeth, then smashed it with a hammer.

Gatland was sentenced yesterday for child cruelty against the youngster and also a 15-year-old boy who said he was subjected to a “never-ending hell” at a house that was like “Fort Knox.”

Judge Stuart Bridge said the 39-year-old must serve 12 years in jail before being considered for parole.

The judge also made an indefinite restraining order barring Gatland from contacting the children.

He found Gatland, who was convicted of two counts of child cruelty at a jury trial, posed a “significant risk of harm” to the public and said: “This is as serious a case that one is likely to encounter.”

“You would beat her on the bottom of her feet with a wooden spoon, I find, regularly and frequently.”

“On one occasion, you tied her with a pair of tights so you can hit her harder.”

“You would make her run on a treadmill … more generally you were doing this as a means of being cruel because that’s what you enjoyed doing.”

“I find that you waterboarded her on at least one occasion, putting a water-soaked rag over her head and running it over her head so she choked.”

The judge said Gatland also threw a bucket of ice water over her head and also subjected a 15-year-old boy to “extreme violence,” including slamming him into a chair with such force that the chair broke.

The judge added: “Both [children] here in my judgment suffered significant physical and psychological harm.”

“For your part, you have been unwilling throughout this process to accept any responsibility or expressed any remorse of what you have done.”

The children cannot be named for legal reasons.

Gatland appeared at Cambridge Crown Court but left the dock for the cells before the judge finished his sentencing remarks.

In court, family members of the girl gasped and smiled as he was jailed for eight years with two years extended license for child cruelty against the girl.

He was also given four years with three years extended license for the boy. The sentences will run consecutively.

Gatland’s crimes were only uncovered after he invited a friend over for a “three-day cocaine binge” to the “Fort Knox” house in Cambridgeshire.

Prosecutor Daniel Taylor shared victim impact statements telling how the girl continued to suffer “extreme anxieties” and feared cold water despite being rescued.

The girl’s foster mother said she displayed “anxieties which are extreme and far above from what I’ve seen from normal behaviors, even from what I’ve seen in traumatized children.”

She added: “She continues to this day to express anxiety about cold water and water running down her face.”

“Sheds are a source of extreme anxiety for [her]. She can become uneasy about anyone behind her and it makes her jump. She uses items and blankets to block her bedroom door and may barricade herself in so we are unable to see her in bed.”

Referring to the girl’s nightmares, the foster mother said: “She told me about a menacing man wearing black with his face she couldn’t see but it was Gatland.”

“The man followed her everywhere she went, he said nothing to her but watched her from a distance — she was very distressed and woke in the early hours.”

“It is widely accepted that in the weeks, months and years ahead, she will undoubtedly require extensive psychiatric and practical things to be able to deal with these issues.”

The court heard that the victim was found hiding in bushes after running away from her foster home on Christmas Day.

The carer added: “She feels safe if Garth Gatland is in prison and says she never wants to see him again.”

The boy said: “Being in that house while those things where going on was hell, while it was going on I felt weak and I felt that I was stuck there forever.

“Had the police officer not removed me, I believe I would still be there in hell. I don’t think he will ever learn of what he’s done and I fear he will just want revenge on me for speaking out against him.

“I have to live with a terrible sense of guilt about being unable to do anything about it and it makes me sad.”

Michael Magarian, Gatland’s lawyer, said: “It may not be full remorse, but he has come to terms with his guilt.”