In one of live television's most toe-curling moments on Sunday night (26 February), the 89th Academy Award descended into chaos in what was supposed to be its highpoint after the wrong film was announced as best picture.

A total fiasco ensued as La La Land was stripped of Best Picture award halfway through the acceptance speech after Faye Dunaway and Warren Beatty announced the wrong winner.

After the cast and crew of the musical flooded the stage to celebrate their win, a clearly peeved Jordan Horowitz delivered the devastating blow – the presenters had got it wrong. The producer told the stunned audience halfway through acceptance speeches: "There's a mistake. Moonlight you guys won best picture. This is not a joke, Moonlight you won best picture. Moonlight best picture."

The car crash scene resembled that from the Miss Universe 2015 when host Steve Harvey announced Miss Colombia Ariadna Gutierrez as the winner of the crown instead of its rightful owner, Miss Philippines Pia Wurtzbach.

PricewaterhouseCoopers, which has overseen the Academy's ballot-counting process for the past 83 years, has since released a statement apologising for the embarrassing mishap. "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."

So what happened?

The unprecedented mix-up occurred after actors Beatty and Dunaway were given the wrong card to present the top prize.

Initially confused, Beatty hesitated and checked the card again, before showing the envelope to Dunaway which prompted her to read the words: "La La Land."

Beatty later returned to the microphone to explain his version of events: "I opened the envelope, and it said Emma Stone, La La Land," he said. "That's why I took such a long look at Faye, and at you [the audience], I wasn't trying to be funny."

The blunder wasn't picked up straight away because only two people know who has won before the winners are announced. Martha Ruiz and Brian Cullinan – who are partners at accountancy firm PwC – count the votes and make sure the results are kept secret and delivered to the venue. They also personally hand the envelopes to each award presenter moments before they walk on stage.

Oscars 2017
Actor Warren Beatty (C) explains a presentation error which resulted in Best Picture being announced as 'La La Land' instead of 'Moonlight' Kevin Winter/Getty Images

"It's up to Brian and I to fully count everything together once, twice and sometimes multiple times to make sure it's correct," Ruiz recently told the BBC.

When Stone addressed the debacle backstage she expressed confusion, saying she had been holding her best actress envelope the whole time. "I don't mean to start stuff but whatever story that was – I had that card. So I'm not sure what happened.

"Is that the craziest Oscar moment of all time? Cool. We made history tonight. Craziest moment."

PwC typically create two complete sets of winners' envelopes for each category and Ruiz and Cullinana are likely to have been standing on opposite sides of the stage throughout the ceremony, alternating between each other in the handing out of envelopes, depending on which side of the stage the presenters enter from. Although no official explanation has been offered, this is where the cards may have got mixed up.

When The Telegraph caught up with Dunaway at the Vanity Fair after party, the 76-year-old insisted her Bonnie and Clyde cast-mate was not to blame: "It was very quick, I can't talk about it. The card read that way. It was a very odd thing. It wasn't Warren's fault."

In light of what transpired, Horowitz is choosing to take the loss in his stride, saying: "Look, we won six Oscars. The picture's been a critical success, a financial success. It's been a wild ride and it ended in spectacular fashion."

Moonlight director Jenkins said he felt better about what happened because Beatty made sure to show him the card first. He told teh press:"I wanted to see the card. Warren refused to show the card to anybody before he showed it to me. And so he did. He came upstairs and he walked over to me, and he showed the card. And everybody was asking, 'Can I see the card'? And he's like, 'no, Barry Jenkins has to see the card, I need him to know.' And he showed it to me. I felt better about what happened."