Brown had a scheduled appearance Friday night at Drai’s Nightclub in Las Vegas, according to the nightclub's calendar.
According to a police statement released Saturday evening, there was an altercation in a room at the resort when the alleged victim tried to take a picture of Brown.
The victim said Brown struck her and took her cellphone, police said. According to the police statement, Brown left before detectives had a chance to speak to him at his hotel room.
The investigation is ongoing.
Brown's publicist said the alleged victim's "statements are unequivocally untrue" and "a complete fabrication."