Justin Bieber Under Investigation For Headbutting Brawl At A-List Bash

Justin Bieber allegedly attacked a restaurant employee for filming him without consent, RadarOnline.com has learned.

Bieber, 22, was at his producer's pre-Grammy party at Serafina over the weekend with Kyle Massey when his night took a turn for the worst. According to reports, he was playing around with the Dancing With the Stars alum when someone began recording him around 2 a.m.

The "Love Yourself" singer asked them to stop, but ended up lunging at them instead to make the video end. He headbutted the victim, and someone quickly called the Los Angeles County Sheriff's Department.

The victim has not pressed charges as of yet, and the LAPD investigation is still ongoing.

"I'm not even sure what happened," his producer, Poo Bear, told RadarOnline.com exclusively of the incident. "I'm not even clear on it. I'm still trying to figure it out myself."

"I did not see it happen," he explained. "But I heard that it was definitely an accident. It wasn't anything that was intentional."

But, Bieber is not a stranger to breaking the law, and most recently assaulted a fan in Barcelona just three months ago.