The girl, who was not identified, was found June 11 in the closet of a home at 2442 S. Newberry Court, police said.

A caseworker from Jefferson County came to the home for a routine check. She found disabled children and a disabled adult at the home with no supervision, officials said.

"She asked to see the girl, looked for her and found her in the closet," Denver police spokeswoman Teresa Garcia said.

The girl was tied with "soft bindings," like towels or sheets, Garcia said. It was unclear how long she had been in the closet, and the girl was not physically hurt, Garcia said.

The social worker called police and immediately removed the children and the disabled adult. The incident is under investigation by the Colorado Department of Human Services, human services departments in Jefferson County and Denver, and Denver police.

Authorities consider the incident "very serious," said state Human Services spokesman Ron Eicher.

"All the residents were immediately removed," he said. "I think that speaks to how serious it is."

Investigators are trying to determine who bound the girl and put her in the closet, Garcia said. She would not say if police suspect the foster parent or the other people in her care. There were at least two others, including an adult, being cared for at the home.

Charges could include child abuse and false imprisonment, Garcia said. Detectives were still conducting interviews Tuesday.

The foster parent, whose name was not released, blamed the incident on the others in her care, Eicher said.

Adding to the confusion, investigators are having a difficult time interviewing the children and disabled adult.

"It's not clear who to pin the blame on," Eicher said.

The girl was placed in the private home by Jefferson County Human Services. When the agency places children and disabled adults, it checks on them in person at least once a month, said spokeswoman Jennifer Watson.

Neighbors said the foster parent - whom they knew only as Yolanda - moved into the home at the end of May along with the developmentally disabled children and adult. The owner of the home, who lives in California, said he did not know the woman personally but she had passed a background check.

The home was operated under the supervision of Consumer Empowerment Corp., a Westminster- based private agency that provides care for children and adults with developmental disabilities.

State inspectors toured the home earlier this month and found "a few deficiencies," Eicher said, although he could not give specifics. The home remained in "good standing" with the state until this incident, he said.

The incident last week could jeopardize the home's license, Eicher said. State and local agencies have suspended all new foster care placements with Consumer Empowerment.

A call to the agency Tuesday was not returned