Woody Harrelson has sent fans on a hunt for a fictional missing dog after posters appealing for information were plastered around Los Angeles as part of a promotional campaign for his new movie.

The actor is currently promoting his latest film, dark comedy Seven Psychopaths, and movie bosses mocked up a flyer, which features a picture of the star in character appealing for the return of his beloved Shih Tzu.

The poster, which is part of an elaborate hoax, has been put up around the streets of Hollywood and sparked a flurry of interest from fans, who have flocked to the character's Twitter.com page to help track down the pooch.

In Seven Psychopaths, Harrelson plays a gangster who becomes infuriated when his beloved dog is kidnapped.