An Illinois couple were arrested on Tuesday for allegedly keeping their 10-year-old daughter captive in their basement for more than a year, believing her to be possessed by a demon.

According to KTRK, police in Waukegan received an anonymous tip that led them to the home of Randy Swopes, 48, and Katherine Swopes, 49.

Police found the girl living in the basement of the house in the 200 block of Liberty Street.

“She was showering with a bucket. She was using the bathroom in a child’s port-a-potty. She had very, very limited access to the outside,” said Commander Joe Florip, Waukegan Police Department.

Police say the girl had been locked in the basement since January.

Her parents told police they believed the girl was “possessed by demon.”

“During the course of the investigation a statement had been made by at least one of the suspects that they believed the 10-year-old child was possessed by a demon,” Frolip said.

The couple was arrested and charged with Child Endangerment and Unlawful Restraint.

The 10-year-old girl and her three other siblings, ages 7, 13, and 15, were removed by the Illinois Department of Child and Family Services.

Randy Swopes is listed with the state’s Murderer and Violent Offender Against Youth registry for Aggravated Battery to a Child in 2008, when he attempted to sew his son’s buttocks closed, according to Waukegan police.