James Gandolfini has apologised to U.S. Defence Secretary Leon Panetta for wearing a questionable wig to portray him in new movie Zero Dark Thirty.

The Sopranos star plays Panetta, the former director of the Central Intelligence Agency (Cia), in the gritty thriller, about the hunt for terrorist leader Osama bin Laden, but he expects the politician will not be impressed with his onscreen image.

The actor explains, "I sent a note to Leon saying, 'I'm very sorry about everything. The wig, everything. You're kind of like my father. You'll find something to be angry about.'"

Gandolfini's comments came during Tuesday's (08Jan13) National Board of Review Awards in New York City, where he presented his Zero Dark Thirty director Kathryn Bigelow with a trophy.

He also told guests at the prizegiving that screenwriter Mark Boal told him Panetta wanted the actor to give him a phone call but joked that he "doesn't know how to get in touch... This is the head of the Cia."