Downey Jr plays Australian actor method Kirk Lazarus (complete with his recycled 'Natural Born Killers' accent), who in turn plays the African American Sgt Osiris, one of a group of actors who unwittingly end up in a real battle while trying to shoot a war movie.

In true overblown method style his character undergoes surgery to blacken his face in order to enhance his portrayal. Downey Jr said: "If it's done right, it could be the type of role you called Peter Sellers to do 35 years ago. If you don't do it right, we're going to hell"

His performance is hilarious and gloriously over the top, but comedies have forever been shunned by the usually straight-laced Academy. However, it isn't the first time the Oscars have brewed up a storm.