One of California's largest private foster care agencies is under fire over allegations of torture and abuse that are outlined in a 76-page lawsuit.

The suit alleges foster care children endured physical and mental abuse of a seven-year period, abuse allegedly covered up by the Rancho Cucamonga-based Interim Care Foster Family Agency, which recruited and supervised the foster parents.

"My old foster parents, they used to make special tools just to torture us, and I was under the age of 10 years old," former foster child Isaiah Sais said at a news conference Thursday.

Sais is one of eight suing the agency, which is part of California's $400 million a year private foster care industry.

"I have been abused verbally, physically and sexually when I was put into foster care," former foster child Shawna Adams said.

The suit claims the children were "caught in an illegal, abusive, violent, concealed, unconscionable 'kids for cash' operation from 2006 to 2013." It goes on to say the foster children "suffered ongoing, unrestrained, terror, torture, corporal punishment, physical and mental abuse and neglect" at the hands of the foster parents that was "covered up/ unchecked by defendant Interim (Care Foster Family Agency)."

"We're letting you hear our voices now because we were silent for too long," former foster child Saleena Galvan said.

"The lawsuit alleges a kids for cash operation that has bilked the government of hundreds of thousands of dollars," attorney L. Wallace Pate said.

The state pays private agencies about $2,000 a month per child. The agencies are allowed to keep as much as 60 percent of the state money to pay for rent, supplies, and personnel to ensure foster children are being cared for, but Pate claims that was not the case with her clients.

"The lawsuit alleges these children lived in seven different homes, none were certified," Pate said. "They were evicted from four facilities and were homeless."

The two foster parents named in the lawsuit had their licenses revoked by the state, but Pate believes the same should happen to the agency which employed them.

NBC4's requests for comment in person and on the phone to Interim Care Foster Family Agency about the lawsuit had not been returned as of Thursday night.