Oscars overseer, PricewaterhouseCoopers, on Monday took responsibility for the Best Picture award announcement mistake. In a statement, the accountancy firm apologised to the winners of the award – the Moonlight team – the La La Land (which was mistakenly announced as the winner] team, presenters Warren Beatty, Faye Dunaway and viewers for the error.

“We are currently investigating how this could have happened, and deeply regret that this occurred,” the statement said.

The firm is believed to have had two sets of envelopes that contained the winners’ names. The presenters were allegedly given the duplicate envelope for the Best Actress award, which had already been awarded to Emma Stone for her role in La La Land, instead of a Best Picture envelope, The Washington Post reported.

Stone, however, claims to have had the card with her name on it all along. “I was also holding my ‘best actress in a leading role’ card that entire time. I do not mean to start stuff, but whatever story that was, I had that card,” Stone said.

The firm and its predecessors have been handling the voting process for the past 83 years. This year, its representatives Brian Cullinan and Martha Ruiz, were the only people who knew the names of the winners before the envelopes were opened during the live telecast of the awards, the English daily reported.

The statement said Dunaway and Beatty had been “mistakenly given the wrong category envelope”. It said the error was immediately corrected. The firm praised the Academy of Motion Picture Arts and Sciences, the nominees, ABC and host Jimmy Kimmel for handling the situation “with grace”. Kimmel said he blamed Steve Harvey for the goof up, referring to the Miss Universe host who had erred in announcing the contest’s winner in 2015.

“Very clearly, even in my dreams this could not be true,” said Barry Jenkins, director of Moonlight, after the clarification. “But to hell with dreams, I am done with it. This is true.” Kimmel ended the show saying he blamed himself for the mistake. ”I knew I would screw this show up, I really did,” he said.