In a rare move, a 19-year-old abused in an Urbandale foster home for years has sued the state for negligence, saying she suffered physically and emotionally because the child welfare case was mishandled.

Malayia Knapp of Des Moines filed the legal action Monday with the State Appeal Board under Iowa’s Department of Management.

It comes after three half-siblings were removed in August from the home of Mindy and Andrew Knapp, when a sibling alleged the child abuse continued.

The ongoing case is one of several in the past year examined by Reader's Watchdog that has raised questions about how foster children are being treated after being adopted by parents who are receiving thousands annually in subsidies.

It also has raised questions about why five children adopted by the Knapps were returned to their home even after child-protective workers found both parents responsible for child abuse and Mindy Knapp was convicted of assault causing bodily injury.

Polk County juvenile judge Colin Witt sealed the ongoing juvenile case this year, saying he wanted to prevent further harm to the children.

The claim filed Monday by Malayia Knapp seeks $500,000 in personal injury damages against Iowa’s Department of Human Services, its workers and all mandatory reporters under its supervision while she and four siblings were wards in the Knapps’ home.

Malayia was 10 when she was adopted by Mindy and Andy Knapp and 12, she alleges, when she was first abused.

In December 2015, the then 17-year-old fled the Knapps’ home barefoot to a convenience store in Urbandale.

When police questioned her, they saw she had bruises, raised black-and-blue welts and open sores, police reports showed. She told social workers and police she and a sister had been locked in a basement room repeatedly.

She told Watchdog in January that she and her siblings were beaten so hard with belts that they broke and were forced to exercise as a punishment by Mindy Knapp for long periods of time.

Malayia Knapp and an 18-year-old brother have aged out of the child-welfare system. Another brother was removed from the Knapps' home after being accused of hurting a sibling.

Three other siblings remained in the home until recently.

Malayia's attorney, Jennifer De Kock, alleges in a letter to the board that her client suffered emotional and physical abuse because of the state’s negligence. Malayia has said repeatedly she wants to protect her siblings from further abuse.

Iowa law generally provides immunity to state workers in most cases, but that immunity can be waived in certain circumstances.

Iowa’s Attorney General has six months to review Malayia’s claim with the Department of Management, De Kock said.