A California foster family has been accused of sexually and physically abusing nine children – including five Turpin siblings placed in their care after they were rescued from horrific conditions at the hands of their biological parents, according to reports.

Foster dad Marcelino Olguin, 62, his wife Rosa, 57, and their daughter Lennys, 36, were arrested in November and released on bail. The case has raised concerns over the glaring failures of a social services system that was supposed to help the Turpin children.

The Turpin family in an April 16, 2016, photo

David and Louise Turpin are pictured with their 13 children in April 2016. (Facebook)

Marcelino Olguin faces multiple counts of lewd acts on a minor age 14 or 15, lewd acts on a minor younger than 14, false imprisonment and willful child cruelty. Lennys Olguin and Rosa Olguin face charges that include false imprisonment, willful child cruelty and dissuading a witness, according to a criminal complaint. They have all pleaded not guilty, records show. 

CALIFORNIA HOUSE WHERE ALLEGED TORTURE OF 13 CHILDREN TOOK PLACE GOES UP FOR SALE, REPORT SAYS

The Turpin siblings were placed with the Olguins in April 2018 a few months after they were rescued from their parent's home in Perris, California, where they had been imprisoned, shackled and starved for years. 

A total of 13 Turpin children ranging in age from 2 to 29 lived in the "house of horrors," which is about 60 miles southeast of Los Angeles. Only the youngest hadn't been abused or neglected, investigators said. 

These Sunday, Jan. 14, 2018, photos provided by the Riverside County Sheriff's Department show Louise Anna Turpin, left, and David Allen Turpin. Authorities say an emaciated teenager led deputies to a Perris, Calif., home where her 12 brothers and sisters were locked up in filthy conditions, with some of them malnourished and chained to beds. Riverside County sheriff's deputies arrested the parents David Allen Turpin and Louise Anna Turpin on Sunday. The parents could face charges including torture and child endangerment. (Riverside County Sheriff's Department via AP)

These Sunday, Jan. 14, 2018, photos provided by the Riverside County Sheriff's Department show Louise Anna Turpin, left, and David Allen Turpin.  (Riverside County Sheriff's Department via AP)

The children were freed after Jordan Turpin then 17, escaped through a window and called 911. Their parents, Louise and David Turpin, were sentenced to 25 years in prison after they pleaded guilty to torturing and imprisoning their kids.

EMOTIONAL STATEMENTS FROM PARENTS, KIDS IN TORTUSE CASE

But what was supposed to be a fresh start for the five Turpin siblings who were given a new home with the Olguins turned into a nightmare, according to The Press-Enterprise and CBS News.

In an affidavit, an investigator said that both minor and dependent adult foster children in the Olguin home were sexually abused, pulled by the hair and locked in their rooms. 

David and Louise Turpin, pictured here in court Wednesday, Jan. 24, 2018, have pleaded not guilty to torture and other charges.

David and Louise Turpin, pictured here in court Wednesday, Jan. 24, 2018, have pleaded not guilty to torture and other charges. (Terry Pierson /The Press-Enterprise via AP, Pool)

A 5-year-old girl was given sleeping pills then forced to stand as the Olguins allegedly rang a bell, sprayed her with water and yelled at her, according to the affidavit. "You don't let us sleep, we're not letting you sleep," the Olguins allegedly told the girl. The news outlet did not identify whether the girl was a Turpin. 

The child was sometimes locked in her bedroom for nine hours a day, the investigator wrote. Four of the girls in the Olguin's care told officials they had been sexually assaulted – including two Turpin children, according to reports. 

Louise and David Turpin who pleaded guilty to imprisoning and abusing their children

Louise Turpin, left, and her husband, David Turpin, right, appear for a preliminary hearing in Superior Court in Riverside, California. (Watchara Phomicinda/The Orange County Register via AP)

The Olguins knew of the shocking abuse the children had suffered at the hands of their biological parents and immediately "pressure-questioned the siblings about their traumatic past," the affidavit says. 

"They forced the siblings to participate in a ‘circle confession talk.' The siblings were forced to admit to their past sibling abuses, which their biological parents had forced them to commit," the investigator wrote. "The Olguins told the siblings non-participation would result in not seeing or visiting with their older siblings in the future."

The Olguins allegedly singled out one of them Turpin children, according to the affidavit and reports. "(The defendants) yelled and cussed at victim #3, demeaned him, isolated him, restricted him to his bedroom, didn't allow victim #3 to talk to his sisters," wrote the investigator, according to The Press-Enterprise.

The social service failures extended to the adult children, who at times did not have a safe place to stay or enough food despite $600,000 in donations from the community, said Riverside County's Director of Victim Services Melissa Donaldson in an interview with ABC News.

Mike Hestrin, Riverside County district attorney, told The Independent that the children "have been victimized again by the system."

"They’re living in crime-ridden neighborhoods. There's money for their education — they can't access it," he said.

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The county launched an investigation into the Turpin's care in October and assigned retired federal judge Stephen Larson to head the probe.

"The County of Riverside is committed to conducting a thorough and transparent review of the services provided to the Turpin siblings and to improve and strengthen the County's child welfare and dependent adult systems," Riverside County Executive Officer Jeff Van Waganen said in a statement in December.

The Associated Press contributed to this report