TMZ reports that the Love Yourself singer head-butted a guest at LA restaurant Serafina early Saturday morning, while attending a fete hosted by his producing partner Poo Bear.
Witnesses said Bieber became enraged when he saw a man taking video of him 'play fighting' with his friend - and former Disney star - Kyle Massey, around 2am.
The report claims Bieber confronted the man, and demanded that he delete the video. When the man refused, things escalated and Bieber allegedly head-butted the gawker.
Someone called 911 to report the incident, but by the time police showed up on the scene, Bieber was already gone.
Photos show him leaving the restaurant that night, ducking into the back of Poo Bear's SUV and hiding his face from the cameras.
The victim reportedly did not want to press charges, but police are continuing to investigate the incident as a possible misdemeanor battery.