MADISON, Wis. (AP) — Prosecutors on Thursday charged the stepbrother of a severely malnourished Wisconsin teen with repeatedly sexually assaulting her beginning around her 10th birthday, in the same year she claims her father and stepmother began confining her to the basement.

Dane County prosecutors also charged the girl's father, 40, and stepmother, 42, with child abuse and first-degree reckless endangerment, which are felonies, as well as a misdemeanor count of neglecting a child.

The couple and the girl's stepbrother, 18, appeared in a Madison courtroom Thursday for an initial hearing.

Prosecutors allege the stepbrother first sexually assaulted the girl in December 2006, which was the month she turned 10, and again from February 2009 through February 2010. He is charged with first-degree sexual assault of a child without great bodily harm, second-degree sexual assault of a child and child abuse — all felonies.

Cash bail between $22,500 and $30,000 was set for each of the three defendants. The Associated Press is not naming the defendants to protect the girl's identity.

A woman believed to be the stepmother's sister declined to comment Wednesday when reached by phone and did not immediately respond to a phone message left Thursday at her home.

The girl has been receiving medical care and is in protective custody, police said Thursday.

The girl, who was 70 pounds when found, gained 17 pounds as of Wednesday, the complaint said.

At least two neighbors said they had called child protective services after seeing the girl rummaging through the garbage for food or being berated by the family.

According to the Department of Children and Families, there had been 10 reports of suspected neglect, sexual abuse or physical since 2006, three of which remain pending. Those three include a Feb. 6 report — the day a passing motorist spotted the girl walking barefoot and wearing thin pajamas.

The department released few details, citing legal reasons.

Of the seven others, six were unsubstantiated or didn't meet the legal definition of abuse or neglect. The department says a May 1997 report of physical abuse was substantiated but didn't note what more happened.

According to the complaint, the girl's stepbrother tried unsuccessfully to have intercourse with her once and he forced her to perform oral sex on him more than 10 times.

She said she told her father and stepmother that the stepbrother was doing "sexual things" to her in 2006, but they thought she was lying. She told a school counselor, and in March 2007 a Dane County child protective services worker and a police detective met with her at the school.

The girl refused to tell them anything, however. The county worker met with her father and stepmother, but they refused to allow her or the police to speak to the stepbrother.

The county later received information that the stepbrother was sent to live with his grandfather to hide from investigators. The father and stepmother expected police to execute a search warrant at their house, so they tried to make the basement bedroom "not look like a dungeon," according to the complaint.

The girl told detectives that her stepmother was responsible for most of her injuries, saying the woman didn't want to marry her father because of her.

After she was transported to the hospital, the father told a doctor and a social worker that family members locked the girl in the basement because they were afraid she might hurt them. They even set up an alarm on the door, put bars on the basement windows and placed cameras on the kitchen pantry in case she tried to steal food.

The girl acknowledged to a detective she has wanted to kill the stepmother and has told her father and the stepbrother she wanted to cut them, but "it was only words."

The girl said she had run away before but her parents had always found her. She fled Feb. 6 because her stepmother threatened to throw her down the stairs headfirst or slit her throat for not picking up papers fast enough, the complaint said.

"I ran away this time because I just couldn't handle it anymore," she told doctors. "I thought she was going to hurt me and throw me down the stairs. I was afraid."

The girl told investigators she sometimes urinated and defecated in the basement because she didn't want to trip the alarm going upstairs or make anyone upset.

She said sometimes her stepmother and her father would make her eat her feces or drink her urine or rub them on her face.

The girl said her stepmother demanded to be called "your majesty" or "master." She said the stepmother told her father that if he wanted to marry her he had to give the girl to her and she was the girl's personal owner, the complaint said.

In a separate case, the stepbrother pleaded no contest last year to charges that he had sexual contact with a child. That criminal complaint says he acknowledged touching the breasts of his 13-year-old girlfriend but denied having sex. The girl told investigators the two had sex in her room about three times, and that he slept in her bed with her mother's knowledge.

The boy pleaded no contest in that case to second-degree sexual assault of a child and three related misdemeanor charges. He was sentenced to three years on probation.