Vitriolic and despicable. These were the adjectives ascribed to the anti-semitic tirade levelled at a Jewish Los Angeles County Sheriff by Mel Gibson, who was arrested for speeding at 2am last Friday. Apparently, Mel has now apologised to the entire Jewish community and has admitted that he’s an alcoholic. Time will tell if this is enough to assuage the legion of Jewish movie execs said to be baying for his blood. If Gibson’s career does not recover then Hollywood will have lost a very rare beast indeed - a movie star that rarely requires a double. Mel, you see, does all his own "ass work".

"Ass doubles" are needed for many reasons: sometimes actors are not comfortable with nudity, sometimes mortals are easier to insure than stars. Often, the director is insistent.

After the filming of You, Me, and Dupree, Owen Wilson said: "The After his arrest Mel may find that no one will cover his back, says ed howker director decided not to use my butt. I don’t know how to interpret that."

To tout for work, agencies send out "zed cards", which include full-body shots as well as close-ups of the models’ finest "ancillary parts". Those who get hired earn $795 for a full body-double shift, and as little as $445 for parts modelling. Elite butt doubles such as Anita Hart get much more. Her body has featured in place of those of Sarah Michelle Gellar, Cindy Crawford and Liz Hurley. Shoots are often done in secret.

Jessica Simpson’s PR machine leaped into action during the making of Dukes of Hazzard, after film crew were quoted as saying: "Jessica’s butt is too flat. We need a rounder, sexier rear end, and better legs."

Studios and agents, it seems, work extremely hard to protect the true identity of the ass on screen. It would be fair to say this option is now no longer available to Gibson.