A man was in custody following the sexual assault of a hotel employee Monday in west suburban Oak Brook.

Authorities were called shortly before noon to Hyatt House at 210 W. 22nd St. for a reported aggravated criminal sex assault, Oak Brook police said in a statement.

Officers were told that the suspect may still be armed and in the area, police said. Officers made an “extensive” room-by-room search for the suspect, who was a 38-year-old man believed to be a relative of a hotel guest, but no one was found.

The victim, a 20-year-old hotel employee, was taken to Elmhurst Hospital for treatment, police said.

The suspect was arrested about 4 p.m. in Chicago, and was transported back to Oak Brook, police said. Charges have not yet been filed, police said.