Kanye West is under investigation for alleged criminal battery.
Reports from TMZ and the New York Post's Page Six column state the 44-year-old musician was involved in an argument that "turned physical". A fan had reportedly asked the rapper for his autograph while he was sitting in his vehicle outside the private club Soho Warehouse.
He allegedly punched the fan who then fell to the ground. The news was first reported by Fox LA.
Local authorities are investigating the alleged incident, and West faces a maximum jail sentence of six months.
Few details of the incident have been reported besides the confirmation of the investigation from the LAPD. The police have not confirmed the type of battery.
Representatives for West are yet to comment.
TMZ published a video of West showing him appearing to yell "Did y'all say that or not? Did y'all say that or not?"
"Cause that's what happened right f****** now."
West was pictured the same evening on the incident with his girlfriend Julia Fox, plus Madonna, Evan Ross, and Antonia Brown.
He has been announced as a headline act for April's Coachella music festival.
Fox, a US actress, revealed details of the couple's relationship in a blog post for Interview Magazine.
"His energy is so fun to be around. He had me and my friends laughing, dancing, and smiling all night," she wrote.
She wrote about the couple's second date and photos were also published by the magazine.
"Ye's flight landed at six and the play was at seven and he was there ON TIME. I was impressed. After the play we chose to do dinner at Carbone which is one of my favorite restaurants. Obviously.
"At the restaurant, Ye directed an entire photoshoot for me while people dined! The whole restaurant loved it and cheered us on while it was happening."