The 24-year-old singer, who is still on probation for assaulting his ex-girlfriend Rihanna in 2009, was arrested and charged with felony assault after a man accused the star of punching him in the face outside the W Hotel in Washington DC at 04:30 on Sunday morning.
The alleged victim, who may need surgery as his nose is broken, told gossip website TMZ.com that Chris went "nuts" when he and a male friend rushed over to get in a photo that the R&B star was taking with two women.
A law enforcement source claimed that the R&B star said: "I'm not into this gay shit, I'm into boxing," before punching the victim.
The man, who later said he didn't understand why Brown would be "so homophobic", is planning to press charges but said he would have accepted an apology from the singer at the scene.
Chris and his bodyguard, Christopher Hollosy, are still in custody at a local police station and they are expected to remain there until Monday morning.
The Love More hitmaker - who was in the city to host a party at the nearby Park and 14th nightclub - wasn't under the influence of any substances or alcohol at the time of his arrest, which could be deemed a violation of his probation and result in him being sentenced to four years in prison.