Los Angeles County sheriff's investigators said the singer was with actress Selena Gomez at the Commons at Calabasas shopping center in Calabasas on Sunday afternoon, when he became involved in a physical altercation with the photographer, who was not identified.
The photographer said Bieber struck him in the face. He said the 18 year old left the scene with Gomez before deputies arrived.
The photographer complained of pain and requested medical attention. Sheriff's officials said he was transported to a nearby hospital, where he was treated and later released.
Officials said the photographer requested that a criminal report be taken on the allegation of battery.
Los Angeles County Sheriff's Department Malibu-Lost Hills Station detectives are investigating the incident.