A Chicago Police officer accused of sexually assaulting a male suspect he was guarding at a hospital has been stripped of his police powers pending an internal investigation.

The Gresham District officer was on duty at the time of the alleged encounter while the suspect was in custody at a city hospital, CPD spokesman Frank Giancamilli said. It was reported to police Sunday evening.

“The allegations are being taken very seriously and the officer has been immediately suspended as detectives conduct an investigation to corroborate the allegations,” the department said in a statement released Tuesday.

The officer is on paid desk duty as CPD’s Bureau of Internal Affairs investigates.

No criminal charges had been filed as of Tuesday evening.