With a drunken Mickey Mouse looming over Sunset Boulevard and a urinating dog in Beverly Hills, Banksy, the British graffiti artist, has hit Los Angeles in the runup to the Oscars on 27 February, in which his film, Exit Through the Gift Shop, is nominated in the best documentary category.

The anonymous artist appears to have produced at least four works which have sprung up this week across the California city, causing the LA Times to ask: "Publicity stunt, or is the elusive artist really here?"

The fact that the works have been uploaded on to Banksy's own website suggests he is indeed in town.

The reaction to the work has been mixed: authorities quickly tore down his reworking of a billboard advert beside a petrol station which was transformed to show a drunken Mickey Mouse, trousers undone, with his arm round the breast of an underwear-clad model while Minnie looks on, apparently drugged-up with bloodshot eyes. The image is entitled Livin' the Dream.

Elsewhere, Jamie Oliver, the TV chef, has been photographed mugging in front of the Crayola Shooter, an image of a child holding a machine gun fed with crayons, not bullets, painted on the back of a branch of Urban Outfitters in the Westwood area of the city.

Charlie Brown Firestarter, meanwhile, is a kerb-level image of the Peanuts character smoking a cigarette and furtively emptying a red fuel can on to the pavement. On a wall in Beverly Hills is stencilled a urinating dog whose yellow trail marks out a falling graph line, evocative of a financial crash.

The appearance of photos of the four works on the artist's own website appears to confirm his authorship, but there were questions over whether it was really in line with his guerrilla spirit to join the pre-Oscar hype.

"It would be rather anti-Banksy for him to participate in an Oscar campaign," said the LA Times.