Actor Will Smith has resigned from Hollywood’s Academy of Motion Picture Arts and Sciences, saying on Friday that his slapping of presenter Chris Rock on stage at this year’s Oscars ceremony was “shocking, painful and inexcusable”.

“I betrayed the trust of the Academy. I deprived other nominees and winners of their opportunity to celebrate and be celebrated for their extraordinary work. I am heartbroken,” Smith said in a statement.

 “So, I am resigning from membership in the Academy of Motion Picture Arts and Sciences, and will accept any further consequences the Board deems appropriate,” he said.

Smith left the audience at last week’s Oscars open-mouthed as he strode up to the stage and slapped Rock across the face after the comic made a joke about his wife’s closely-cropped head.

The actor then returned to his seat but shouted obscenities at the shocked comedian.

It was unclear whether Rock was aware that Pinkett Smith has alopecia, a condition that causes hair loss, when he made a reference to the 1997 film GI Jane in which actress Demi Moore shaved her head.

Half an hour after the astonishing attack, Smith was awarded the Best Actor Oscar for his role in the sports biopic King Richard and made a tearful speech as he received the statuette.

There have been conflicting reports in recent days over whether Smith was asked to leave the ceremony, with the Academy saying he refused to go.

The group said this week it was starting disciplinary action against the actor – only the fifth Black man to win the movie world’s highest individual award for a man – and warned he could face a rare expulsion.

David Rubin, president of the film academy, said the Academy accepted Smith’s resignation but would continue with disciplinary proceedings.

The matter is due to be discussed at the group’s next board meeting on April 18.

In his statement, Smith added: “Change takes time and I am committed to doing the work to ensure that I never again allow violence to overtake reason.”