A Chicago police officer has been charged with criminal sexual assault of a minor, according to police.

Officer Eugene Ciardullo, 51, was taken into custody after being identified by an 18-year-old woman as the offender with whom she "had a sexual relationship" when she was underage, Chicago police said in a statement.

At the time, Ciardullo was working as a part-time security guard at the victim's school, authorities said.

"A part-time security officer at the Chicago High School for Agricultural Sciences was removed from his position in December in response to serious allegations, and the individual is no longer an employee of Chicago Public Schools," CPS spokesperson Michael Passman said in a statement.

"The school responded promptly and followed proper protocols after it became aware of the allegations, and CPS is cooperating with law enforcement as it investigates the matter," Passman added.

Ciardullo was arrested at his home in the 8300 block of South Keeler in the city's Scottsdale neighborhood at around 1 p.m. on Friday, according to police.

He was charged with one felony count of criminal sexual assault of a victim between 13 and 17 years of age and was expected to appear in bond court on Sunday afternoon.

Ciardullo has been with the Chicago Police Department for 21 years, officials said, and is currently assigned to the 9th District on the city's Southwest Side.

It was not immediately clear if Ciardullo was removed from duty, or if the department had taken any disciplinary action.

"The Chicago Police Department is currently also investigating this incident internally and administratively," CPD spokesperson Anthony Guglielmi said in a statement.

"We remain committed to the highest levels of accountability for our officers and members and will not tolerate any activity or actions that undermine the integrity of the hard working men and women of our Department," Guglielmi added.