Peter Franks is a diamond smuggler, portrayed in the film Diamonds Are Forever by British actor and stuntman Joe Robinson.
In both the film and the book, James Bond takes his identity in order to meet Tiffany Case. In the book, Bond takes the identity of Franks because the two look similar. Franks never physically appears.
In the movie, Franks is taken into customs of the Dover Ferry terminal so Bond can take his identity, and after he escapes he goes to Amsterdam to meet Tiffany. Bond, knowing he can’t let Tiffany meet the real Peter Franks, heads for her apartment, where he encounters Franks in the elevator, and Bond’s cover is blown when he is about to attack him. A long and brutal fight then ensues, and Bond finally kills Franks by knocking him off a balcony with a fire extinguisher, where he falls to his death. Bond then switches his wallet with Peter’s, to make Tiffany think he killed James Bond, thus maintaining his cover as Franks. The two then smuggle the diamonds to Los Angeles within the body of Peter Franks.