Oscars 2017: The mystery of the wrong envelope has finally been solved

This year's Academy Awards proved unforgettable, after La La Land was mistakenly named Best Picture instead of Moonlight

Oscars history happened in a multiplicity of ways this year - Moonlight's landmark win saw the first Best Picture winner centered on an LGBTQ character, as well as being the lowest-budgeted.

That said, this year may mainly be remembered for a less joyous historic occurrence, perhaps the greatest gaffe in all Oscar history: with presenters Warren Beatty and Faye Dunaway mistakenly naming La La Land the Best Picture winner, after being handed the wrong envelope.

Eagle-eyed viewers soon noticed that the envelope Beatty was handed was, in fact, labelled 'Actress in a Leading Role', which itself went to La La Land's Emma Stone; except, Stone herself noted she was still holding her winning envelope.

Time for some answers from accounting firm PricewaterhouseCoopers, who for 83 years have been in charge of keeping the secrecy around the night's winners, with the envelopes used in the ceremony kept locked in two identical briefcases - featuring two identical sets of envelopes.

"PwC takes full responsibility for the series of mistakes and breaches of established protocols during last night's Oscars," a statement from the firm reads. "Partner Brian Cullinan mistakenly handed the back-up envelope for Actress in a Leading Role instead of the envelope for Best Picture to presenters Warren Beatty and Faye Dunaway. Once the error occurred, protocols for correcting it were not followed through quickly enough by Mr Cullinan or his partner."

Both Cullinan and Martha Ruiz were the only two individuals who knew the results ahead of time, tasked with leading the count and recount before prepping the envelopes, keeping the briefcases safe, and then handing out the envelopes on the night. This marked their fourth consecutive year of carrying out the role.

However, many are now pointing out - with Variety citing two insider sources - that Cullinan was tweeting throughout the night and that a now-deleted picture of Emma Stone may have potentially distracted him enough to cause the gaffe.

Ironically, Cullinan had previously discussed his work in an Academy-released piece on the pair, stating: "The producers decide what the order of the awards will be. We each have a full set. I have all 24 envelopes in my briefcase; Martha has all 24 in hers. We stand on opposite sides of the stage, right off-screen, for the entire evening, and we each hand the respective envelope to the presenter. It doesn’t sound very complicated, but you have to make sure you’re giving the presenter the right envelope."