An accountant for the Academy Awards is being blamed for the blunder that resulted in La La Land being wrongly mnamed best picture at the Oscars ceremony.
Brian Cullinan, who media reports said had been tweeting backstage shortly before the mix-up, gave presenters Warren Beatty and Faye Dunaway the wrong envelope, PricewaterhouseCoopers (PwC) said in a statement.
In a gaffe that stunned the Hollywood audience and television viewers worldwide, the hosts named La La Land as winners of the top Oscars award instead of Moonlight.
The mistake was not rectified until La La Land producer Jordan Horowitz, on stage for the acceptance speech, put things right.
"Guys, guys, I'm sorry. No. There's a mistake," he said. "Moonlight, you guys won best picture. This is not a joke."
As it happened: Look back at RNZ's live blog of the Oscars ceremony.
In a statement PwC said Mr Cullinan had "mistakenly handed [the hosts] the back-up envelope for actress in a leading role instead of the envelope for best picture".
Just two accountants know the names of the 24 winners after their names are placed in two sets of sealed envelopes.
Tradition has it the envelopes are taken separately in two briefcases to the Academy Awards venue.
The two accountants - in this case Mr Cullinan and Martha Ruiz - are driven there separately.
The pair then stand offstage at opposite sides and hand envelopes to the presenters as each category is announced.
The Wall Street Journal and celebrity website TMZ.com reported that Mr Cullinan had posted a backstage photo of actress Emma Stone on social network Twitter minutes before the mix-up.
The photo, from Mr Cullinan's Twitter account, was later deleted but was still viewable on Monday on a cached archive of the page.
Last week, Mr Cullinan told the Huffington Post the procedure for dealing with the hand-off of an incorrect envelope, other than signalling to a stage manager, was unclear. "It's so unlikely," Cullinan told the Huffington Post.
A brand management expert said it could take years for PricewaterhouseCoopers to recover.
"This is not advanced math. PwC had to get the right name in the right envelope and get it to the right person," said Tim Calkins, a marketing professor at Northwestern University, calling the blunder a "bit of a branding tragedy".
- BBC / Reuters