Will Smith was asked to leave the Oscars ceremony after hitting Chris Rock but refused, the Academy says.
The event’s organising body also said it had initiated “disciplinary proceedings” against Smith.
Smith slapped Rock after the comic made a joke about his wife Jada Pinkett Smith’s shaved head, a result of the hair-loss condition alopecia.
The actor – who won the first Oscar of his career at the ceremony – has since apologised.
In its statement, the Academy of Motion Picture Arts and Sciences said: “Mr Smith was asked to leave the ceremony and refused, [but] we also recognize we could have handled the situation differently.”
It also announced it had “initiated disciplinary proceedings against Mr Smith for violations of the Academy’s Standards of Conduct”.
These include inappropriate physical contact, abusive or threatening behaviour, and compromising the integrity of the Academy, it said.
The Academy said action may be taken at its next board meeting on 18 April. That may include “suspension, expulsion, or other sanctions,” the statement said.
It also apologised directly to Rock, as well as nominees, guests and viewers.
Meanwhile, Rock said he is “still processing” the incident in his first public comments since the ceremony.
“How was your weekend?” he jokingly asked the crowd at a stand-up show in Boston, before saying he did not plan to address the incident at length.
“I’m still processing what happened, so at some point I’ll talk about that,” Rock told the crowd. “It’ll be serious. It’ll be funny, but right now I’m going to tell some jokes.”
Reacting to the Academy’s statement, Jimmy Kimmel, who hosted the Oscars in 2017 and 18, said on his talk show: “Usually when someone’s asked to leave and refuses to go, that’s when security comes in and takes that person away.
“But in this case, they decided to give him an Oscar and let him back on stage to speak.”
‘Sends the wrong message’
One of this year’s co-hosts, Wanda Sykes, said she found the incident “sickening” and that it was “gross” that Smith was allowed to stay to accept his award.
“I physically felt ill, and I’m still a little traumatised by it,” she told talk show host Ellen DeGeneres. “And for them to let [Smith] stay in that room and enjoy the rest of the show and accept his award, I was like, ‘How gross is this?’ This sends the wrong message.
“If you assault somebody, you get escorted out the building and that’s it. But for them to let him continue, I thought it was gross.”
She also told DeGeneres she had spoken to Rock after the show. “The first thing he said is, ‘I’m so sorry.’ I was like, ‘Why are you apologising?’ He was like, ‘It was supposed to be your night.
“‘You and Amy [Schumer] and Regina [Hall] were doing such a great job. I’m so sorry this is now gonna be about this,'” Sykes said Rock told her.
On Monday, another former Oscars host, Whoopi Goldberg, who is one of three governors in the Academy’s acting branch, said: “We’re not going to take that Oscar from him.
“There will be consequences I’m sure, but I don’t think that’s what they’re going to do, particularly because Chris [Rock] said, ‘Listen, I’m not pressing any charges.'”
The incident on Sunday night happened just before Smith won the Oscar for best actor, when the comedian Rock was on stage to present the award for best documentary.
Rock made a quip about Pinkett Smith’s shaved head. The joke referred to the 1997 film GI Jane, in which Demi Moore played the title role with a severe buzzcut.
Pinkett Smith rolled her eyes at the comment, while Smith appeared to initially laugh and clap his hands before he was seen on stage, walking up to Rock.
The comedian looked stunned in the immediate aftermath of the incident, but told the audience: “That was the greatest night in the history of television.”
In his apology, Smith said his behaviour was “unacceptable and inexcusable”.
“I would like to publicly apologise to you, Chris,” he said in a statement. “I was out of line and I was wrong.”