An Illinois man is suing the state's Department of Human Services, claiming the social worker assigned to his case sexually abused him.

According to WBBM-TV, 53-year-old Christy Lenhardt is accused of seducing and sexually abusing the 24-year-old man, whom we are not identifying due to the nature of his allegations, while he was at a state mental institution in suburban Chicago.

The man is being represented by attorney Joe Cecala, who said Lenhardt "engaged in all kinds of various sexual misconduct" with his client while he was at the Elgin Mental Health Center.

The lawsuit claims that Lenhardt kept the man as a sex slave for much of the last three years.

“She’s accused of manipulating and seducing our client, repeatedly," Cecala said, adding that he has "evidence of her perversion," including emails and photos.

Cecala's client ended up at the center after he pleaded not guilty by reason of insanity in 2014 for battery against a police officer. According to the patient's mother, he was only supposed to be in there six to 12 months, but they are accusing Lenhardt of making excuses to keep him at the facility.

In a statement to police and the news, the man's mother said: “They assured me that they were going to help me with my child. What she did to my son was wrong.”

Cecala and other attorneys are also suing two other psychiatrists and the center's director, who allegedly knew about the abuse and didn't come forward, according to the lawsuit.

Lenhardt was fired from the center in July after the patient was released and complained about the alleged abuse.

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Lenhardt has not been charged with a crime, but attorneys said state police are investigating. Media outlets have not been able to reach Lenhardt. A spokesman for the Elgin Mental Health Center declined to comment on the pending lawsuit.