A day care in Chicago in under investigation after it was found to have a registered sex offender working in its kitchen, MyFoxChicago.com reported.

Eric Ellis, registered on the Illinois State Police's sex offender website, was found by the TV station to have been working in the upscale, eco-friendly Little Green Tree House day care.

Ellis told the station that he got the job through a temp agency and that both the agency and the day care center knew of his criminal record, having informed both establishments himself.

Managers of the Little Green Tree House, however, disagreed with that statement and appeared stunned to learn of his background, MyFoxChicago.com reported.

One of the managers told the station that they use a temp service when the kitchen staff is sick. The service is responsible for checking the background on those it employs, she said.

“Obviously, we are not OK with (the agency’s background check),” she told the station. “He’ll be going home immediately.”

Ellis was convicted of criminal sexual assault for repeated sexual abuse of a 14-year-old girl in 2000 and 2001, according to court records.

He was placed on the sex offender registry after serving four and a half years in prison and was barred from working around children, the station reported.

"I work through a temp service. I don't mess with kids,” Ellis told MyFoxChicago.com.

Food Team Inc., the temp agency Ellis was working for, refused to speak with reporters from MyFoxChicago.com.

Parents of children at the day care had mixed reactions to the news of Ellis’ record.

"My sister, who is the parent of this child,” one aunt told the station, “they pay a lot of money and you would expect excellent service and excellent background checks."

Another parent, Tina Keuning, said: "I completely believe it was just an oversight by the temp agency ... but we're so happy here. I feel like I'm glad it's caught."

The Illinois Department of Chidren and Family Services has launched “both a child protection investigation and a day care licensing complaint,” a spokesman s told the station, adding it is the responsibility of the day care to ensure the background checks are done.

Click here for more on this story from MyFoxChicago.com.