Chicago police are investigating allegations that a group of officers had improper sexual relations with newly arrived immigrants.

Several officers from the Ogden District, covering Lawndale and Little Village, are being targeted in the probe, including at least one facing accusations of having sexual contact with a minor, law enforcement sources said Thursday. 

As the city has struggled to accommodate an influx of new arrivals being sent from the southern U.S. border, controversy has brewed over the decision to temporarily house many of them at police stations. Despite the stiff criticism, allegations of serious misconduct by police officers had not previously been reported.

A police spokesperson said both the department’s Bureau of Internal Affairs and the Civilian Office of Police Accountability are investigating the new allegations. 

Police officials wouldn’t say whether any of the officers had been stripped of their police powers, or whether the matter had been referred to Cook County prosecutors. A COPA spokesperson didn’t respond to a request for comment.