05/27/2009 AT 08:20 PM EDT
is facing more legal trouble – this time from a man who claims he was beaten up by the singer's bodyguard.
Robert Rosen is suing Brown, 20, for personal injury, alleging he was roughed up after taking a snapshot of Brown at a Los Angeles fitness club on March 13, according to the lawsuit filed in L.A. Superior Court.
Rosen claims he was chased by the bodyguard, who yelled at him after taking the picture while Brown was playing basketball, and attempted to run away, but an employee of L.A. Fitness Club allegedly "tried to block [Rosen's] exit and grabbed his clothing and body."
Rosen broke free but then fell down a flight of stairs, the lawsuit says. The bodyguard then allegedly "picked [Rosen] up by his shorts, and physically assaulted him," according to the lawsuit. Rosen adds he was "severely injured and disabled, both internally and externally," claims he was falsely imprisoned, and is seeking damages covering his medical bills and emotional distress.
Rosen, who's also suing the fitness club for negligence and other claims, argues its employees did not adequately protect him.
Brown's lawyer, Mark Geragos, says, "This is a specious and frivolous lawsuit by one of the paparazzi seeking publicity and a payday. He’s done this before and lost. We will vigorously defend against this."
An L.A. Fitness Club manager at the gym at issue had no comment.
The lawsuit makes no mention of whether police were called. A Los Angeles Police Department spokesperson had no knowledge of the incident.