Sacha Baron Cohen has been warned not to turn up to the Oscars on Sunday as the Dictator, the British comic's latest alter ego and the subject of his forthcoming film.

US reports suggest that Baron Cohen is planning some sort of stunt in an echo of his appearance at the MTV Movie awards in 2009, where he was lowered bottom first onto an apparently shocked Eminem (the rapper was later revealed to be in on the joke) while dressed as flamboyantly gay Austrian fashionista Brüno. However, a spokesperson for the Academy of Motion Picture Arts and Sciences told Deadline: "We would hope that every studio knows that this is a bad idea. The red carpet is not about stunting."

Baron Cohen has been invited to attend the Oscars as part of the ensemble cast for Martin Scorsese's 3D fantasy Hugo, which is up for 11 awards. However, organisers have long been keen to discourage attendees from promoting their upcoming ventures: the Academy has only just begun to allow adverts for new films to be shown during commercial breaks for the Oscars telecast. Baron Cohen, 40, was invited to present an award in 2007 but opted out after he was refused permission to do so while dressed as Borat, his earlier and perhaps best-known creation.

The Dictator, described as "the heroic story of a dictator who risked his life to ensure that democracy would never come to the country he so lovingly oppressed", sees the comic as the Saddam Hussein/Muammar Gaddafi-style autocratic leader of fictional Middle Eastern nation the Republic of Wadiya. Borat and Brüno director Larry Charles is once again behind the camera and the film is due out in May.

The 84th Academy Awards are due to take place at the Kodak Theatre in LA on Sunday, with Billy Crystal hosting for the ninth time.