PORTAGE, Wis. -- Police investigating a child abduction went to a Portage residence and said they found an 11-year-old boy who had been severely tortured and then found his mother Friday buried in the yard -- a possible homicide victim.

SLIDESHOW: View Images Of Portage Investigation | VIDEO: Watch The Report | VIDEO: Neighbors React To Investigation

Police were originally called to the home in the 300 block of Onedia Street on a report of a child abduction. The National Center for Missing and Exploited Children tipped Portage police that a 2-year-old from Orlando, Fla., who had been missing since last September, might be at the home with her mother, who did not have custody.

Portage police said they found the missing Florida 2-year-old at the home Thursday and that the child was OK, WISC-TV reported.

While at the home, police said they found physical evidence that the 11-year-old boy was the victim of serial physical abuse and malnutrition. The boy was found locked in the closet with severe burns on his face, hands and feet. The abuse was allegedly in the form of being burned with scalding water as punishment for failing to clean, police said. The boy is currently in guarded condition in a hospital, authorities said.

Authorities said that they took photos of the boy's injuries, which included head wounds, burnt fingers and toes, scratches to the torso. They said that there were signs of systematic torture and abuse and that the boy had been educationally neglected.

"This child looks very similar to, maybe even a little worse than, pictures you see of survivors coming out of concentration camps in World War II," said Columbia County District Attorney Jane Kohlwey.

Portage Police Chief Ken Manthey said the alleged torture was the worst he had seen in 30 years as an officer.

At the scene, the boy's 15-year-old sister tipped investigators to search the backyard for their mother. At about 2:20 p.m. Friday, police uncovered the 37-year-old woman's body in the home's backyard.

Police said that they believe the woman might have been dead since Memorial Day weekend. An autopsy is scheduled for Saturday to determine how the woman died.

The Columbia County medical examiner said that preliminary results from Saturday's autopsy are consistent with strangulation. Multiple injuries were also identified that officials said are consistent with physical abuse.

Columbia County officials said that further forensic testing is ongoing and that the death remains under investigation.

The dead woman's children -- the boy and a 15-year-old girl -- were living with two other adult women and an adult man.

Authorities said that the two women -- identified as Candace Clark, 23, and Michaela Clerc, 20 -- are currently in custody on tentative charges of physical harm to a child and obstruction. Police said both women lied about their identities.

Police said that they also found two other children in the house, a 1-year-old girl and 3-month-old girl. The youngest girl had evidence of malnutrition as well, police said.

Police said a man who escaped from the residence was arrested Friday in Milwaukee. Authorities said 27-year-old Michael S. Sisk, also known as Jeremy A. Gunther, was taken into police custody at a Milwaukee bus station on Friday afternoon.

Neighbors who spoke with WISC-TV said that they didn't know much about the family who lived at the Oneida Street home.

One next-door neighbor said that she rarely saw the family outside and that the windows of the house were covered in tinfoil.

One neighbor said she had been watching the police investigation out of her bedroom window, which overlooks the backyard of the home where authorities said they uncovered a woman's body.

"Being able to look out my window and see them shifting sand, looking for bodies and evidence -- it's just very different," the neighbor said.

That neighbor said she was shocked to hear that police had uncovered a body buried in the backyard. She said residents of the house kept a sporty looking car parked over the area police were digging.

Stay tuned to WISC-TV and Channel 3000 for continuing coverage.