Michael Keaton spoils Batman the night before opening in resurfaced video from 1989

Resurfaced footage shows the moment Michael Keaton ruined a huge Batman plot twist on Late Night with David Letterman the day before the film was released in cinemas.

The Birdman actor played the titular hero in the 1989 movie battling against Jack Nicholson’s The Joker.

He told the host “Bruce Wayne witnesses the murder of his parents when he’s a kid,”, who asks if the Joker was responsible for this.

He revealed “Yeah, but he doesn’t know it ‘till later – I’ve kind of blown the plot here.” to the noise of frustration from the audience.