Comedienne Ellen Degeneres stunned Oscar winner Matthew Mcconaughey during his appearance on her US chat show when she gave away one of his new film's biggest surprises.

McConaughey was promoting Interstellar on the show when the host blurted out the name of a surprise co-star.

Journalists who have seen previews of the new Christopher Nolan movie have been sworn to secrecy about the film's plot and twists until after it is released this weekend, but DeGeneres accidentally let it slip that another Oscar winner makes a surprise appearance.

Her comments had to be blocked when the show aired.


The actor appeared briefly annoyed when he asked the host, "Me and who?" before trying to stop her from repeating his co-star's name.

Red-faced DeGeneres quickly realised her mistake and said, "It'll be edited out" before adding, "When they see the movie word will get out."

McConaughey then swore the members of the studio audience to secrecy, stating, "It's just between us."