The producer of La La Land, surrounded on stage by the rest of the cast, was midway through his acceptance speech when he was told that they had not in fact won the award.
The biggest mistake made at the Oscars occurred on Sunday evening when actors Warren Beatty and Faye Dunaway read out the wrong name for Best Picture winner.
American film La La Land scored big at the 70th British Academy Film Awards.
The nominees for the 2017 Oscars has been announced and once again La La Land is leading the pack.
The film stole the limelight at the 74th Golden Globe Awards earlier this week, where it won in all seven of the categories that it was nominated for.