LOS ANGELES • An accountant for the Academy Awards botched the meticulous procedure for announcing the Oscar for Best Picture when he handed victory to La La Land before declaring Moonlight the real winner, PricewaterhouseCoopers (PwC) said on Monday.

Accountant Brian Cullinan, 57, said to have been tweeting backstage shortly before, gave presenters Warren Beatty and Faye Dunaway the wrong envelope for the movie industry's top award on Sunday, the accounting firm said in a statement.

In a gaffe that stunned the Dolby Theater crowd in Hollywood and TV viewers, "Cullinan mistakenly handed the back-up envelope for Actress in a Leading Role instead of the envelope for Best Picture" to Beatty and Dunaway, PwC said. "Once the error occurred, protocols for correcting it were not followed through quickly enough by Mr Cullinan or his partner."

Mr Cullinan, a partner at PwC, had tweeted a backstage photo of actress Emma Stone moments before the error, say reports, and had reportedly been tweeting frequently all night.

By Monday afternoon, the photographs had been taken down.

The moment Dunaway called out La La Land, Mr Cullinan and his colleague Martha L. Ruiz knew immediately that Moonlight was the winner. But it took more than two minutes before La La Land's producer Jordan Horowitz, already on stage with other producers, grabbed the microphone, saying: "I'm sorry, no, there's been a mistake. Moonlight, you guys won Best Picture. This is not a joke."

It then took three hours for PwC, which has been overseeing Academy Awards balloting for 83 years, to confirm that Beatty and Dunaway received the wrong category envelope.

PwC said early on Monday it took full responsibility and apologised to the casts and crews of La La Land and Moonlight.

"We sincerely apologise to Warren Beatty, Faye Dunaway, (host) Jimmy Kimmel, (broadcaster) ABC and the Academy, none of whom was at fault for last night's errors," it said in its statement.

"(Cullinan) is very upset about this mistake," Mr Tim Ryan, PwC's United States chairman, told Variety. "And it is also my mistake, our mistake and we all feel very bad."

The Academy of Motion Picture Arts and Sciences, which organises the Oscars, apologised and said it was committed to upholding the integrity of the Oscars.

"We have spent last night and today investigating the circumstances and will determine what actions are appropriate going forward," it said in a statement.

Why did it take minutes to fix the error? Mr Gary Natoli, the telecast's stage manager, said: "It wasn't until just before I jumped onstage that it was confirmed by both Brian and Martha as the winner being incorrect."

Ms Ruiz and Mr Cullinan apparently needed to find each other backstage to confer before speaking up. It was one of the most surprising reversals in Oscar history.

And for the academy, which was criticised last year for failing to nominate any minority actors for the second consecutive year, there was a missed moment: Instead of a proper celebration of black film Moonlight, there was a televised scene of confusion, disbelief and astonishment.

"I read the card that was in the envelope," said an embarrassed Beatty, 79, who carried the envelope to the Governor's Ball after the show. "I thought, 'This is very strange because it says best actress on the card.' And I felt that maybe there was some sort of misprint."

Dunaway, 76, declined to comment.

"Except for the end, it was fun," Kimmel said on Monday, referring to the show. "You know it's a strange night when the word 'envelope' is trending on Twitter," he said on his ABC show Jimmy Kimmel Live.

While the Best Picture mix-up took top spot in the evening's embarrassments, the ceremony was beset with smaller blunders.

During the "in memoriam" segment, the name of celebrated Australian costume designer Janet Patterson, who died last year, was accompanied by a photograph of Jan Chapman, an Australian movie producer who is alive and well.

REUTERS, NYTIMES, WASHINGTON POST