Moonlight was awarded the best picture Oscar after La La Land was handed it in a major mix-up.
Warren Beatty and Faye Dunaway took to the stage to announce the winner, but Warren hesitated as he prepared to read the name.
He handed the envelope to Faye who read out La La Land to enormous applause.
As the stage was filled by stars Emma Stone, Ryan Gosling and producers Jordan Horowitz and Marc Platt began their acceptance speeches, members of the Oscars crew were seen running across the back of the stage.
Producer Fred Berger then appeared and told a stunned crowd: “There’s a mistake. Moonlight you guys won best picture. This is not a joke, Moonlight you won best picture. Moonlight best picture.”
The accountancy firm which oversees the results of the Oscars, PwC, has apologised and said Warren Beatty was given the wrong envelope.
Their full statement reads:
"We sincerely apologize to Moonlight, La La Land, Warren Beatty, Faye Dunaway, and Oscar viewers for the error that was made during the award announcement for best picture," said PricewaterhouseCoopers, which has overseen the Academy's ballot-counting process for 83 years.
"The presenters had mistakenly been given the wrong category envelope and when discovered, was immediately corrected. We are currently investigating how this could have happened, and deeply regret that this occurred. We appreciate the grace with which the nominees, the Academy, ABC, and Jimmy Kimmel handled the situation."