Christina Aguilera and her bodyguard are being sued by a photographer who claims the guard punched and spat on him after he snapped some unflattering pictures of the 'Beautiful' singer outside a Hollywood nightclub last year.

According to the lawsuit filed Tuesday by celebrity paparazzo David Keeler in Los Angeles Superior Court, Keeler was staked out at the entrance of the nightspot Nacional early May 21 of last year, hoping to capture Xtina and other celebrities leaving the popular night spot.

Keeler claims that he spotted the singer exit the nightclub about 2am and that she 'appeared to be intoxicated and needed assistance walking to the car.' In court documents Keeler says that as he was taking photos of the stumbling Aguilera he was punched in the face and spat on by bodyguard Vernon Warren, who according to Keeler, said the paparazzo 'needed to learn respect.'

Keeler claims the beatdown continued after Warren took off with Xtina in her car, when Warren had asked another man to continue where he left off. The unnamed person supposedly hit Keeler in the back and told him he was not wanted there.

Aguilara's representative, Meghan Prophet, issued a rebuttal Wednesday. 'Christina has no reason to believe that such an incident did occur, nor did she witness such an incident.'

The lawsuit also names Anthony Davis, owner of A.D. Entertainment, and Three Wishes Tour Inc., who was said to have hired the bodyguard.

The photographer is seeking unspecified damages and punitive damages.