Michael Keaton has revealed he actually found running naked through the middle of New York for new movie Birdman quite enjoyable.

The former Batman star's latest film - from Mexican director Alejandro Gonzalez Inarritu, of 21 Grams and Babel fame - sees him play an actor once famous for starring as a movie superhero, trying to revive his flagging career by directing and starring in an ambitious Broadway production of a play he has also re-written himself.

One of the comic highlights of the dark comedy is when his character Riggan pops out for a cigarette between scenes and the stage door blows shut, trapping his dressing gown.

The fragile actor is forced to run around the side of theatre and through Times Square to get back in through the front of the theatre - wearing only his underpants.