Witnesses told Eyewitness News they saw Bieber in a black Dodge Ram strike the man, but it appeared to be an accident.
There were many photographers at the scene with cameras flashing as Bieber left a church event at the Saban Theatre.
Video shows Bieber trying to leave the event as photographers surrounded his car and one was hit in the legs as Bieber's truck accelerated.
Bieber remained at the scene and spoke to the man as help was called.
Kourtney and Khloe Kardashian were also at the event, but were not involved in the collision. Their Aston Martin was parked right in front of the collision scene, but they were not there when it happened.
The injured man was seen at the scene being treated by paramedics and then moved on a stretcher into an ambulance, his leg in a cast.
Some time after the collision, Kardashian was seen with her sister Khloe and a friend in an Aston Martin arriving at Craig's restaurant in West Hollywood.
Beverly Hills police said no one was cited or arrested at the scene and there was not believed to be any criminal activity involved.