Ten children also found in US cellar horror case (VIDEO)

Ten children found in the care of a woman accused of locking up four mentally disabled people in a filthy Philadelphia basement have been taken into protective custody

(GlobalPost reports: 4 disabled adults found in Philadelphia basement)

Meanwhile, a fourth suspect has been arrested in connection with the case, ABC News reports.

Linda Ann Weston, 51, Eddie Wright, 51, and Gregory Thomas, 48, were arrested Sunday and charged with holding four adults with the mental capacity of 10-year-olds in a basement behind a steel door that was chained shut for as long as 11 years.

The disabled captives — three men and one woman found by the landlord during a check of the two-story apartment house in the working class Tacony neighborhood — were likely victims of Social Security fraud, Philadelphia Police Sergeant Joseph Green said, Reuters reports. 

Jean McIntosh, 32, the daughter of the accused ring-leader of the scheme has now been arrested and charged with kidnapping, unlawful restraint, and false imprisonment. Police believe McIntosh cashed in the social security checks of the disabled adults, ranging in age from 29 to 41.

Philadelphia Police Commissioner Charles Ramsey told CNN on Wednesday that 10 children aged from 2 to 19 had now also been taken into care, including the niece of the prime suspect Linda Weston, reported missing in 2009.

Ramsey told CNN: 

"This is a very sad story. It makes no sense. When you look at the kids, the psychological trauma is pretty apparent. It's some of the worst things I've ever experienced."

The 10 were being evaluated at a hospital for signs of abuse or malnutrition, with Reuters quoting a police spokeswoman as saying: "A few of them appeared to be underweight."

Two of those found may be the biological children of two of the imprisoned adults, the ABC quotes police as saying.

According to Reuters, police say there may be as many as 50 victims of the group in multiple states.

Linda Weston was convicted more than 30 years ago of starving to death a 25-year-old man in her apartment in North Philadelphia and served eight years in prison, Reuters reports.