A photographer snapping Rihanna and Chris Brown at Brown's 19th birthday party in Florida on Monday has accused the singer's bodyguards of beating him up and stealing his camera.

Tampa Bay Times photographer Luis Santana, 25, claims he was chased and pinned down by minders, who swiped his $3,000 camera, when he tried to take pictures of Brown arriving at St. Petersburg's Vintage Ultra Lounge.

Santana alleges he was left with abrasions and bruises on his chest, back and arms.

He says, "I've shot many many celebrities and this was just another notch on my belt. Then it just turned sour."

Police are investigating four unnamed male suspects, who left the scene in a limousine.