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.
