Spider-Man actor James Franco has blasted the paparazzi for their harassment of his co-star Sienna Miller, after she was constantly "hounded" on the set of their latest film, Camille.

Franco, 28, admits he "feels bad" for the Factory Girl star, whose every move is traced by waiting paparazzi.

He says, "We were out working, and wherever she went she'd be hounded. If we went to a cafe, a photographer would run in and make a story out of it.

"I feel bad for Sienna that she has to put with that all day, every day."