Grey's Anatomy stars T.R. Knight, left, and Isaiah Washington pose for photographers after the Emmy Awards in 2006. Washington has apologized to Knight for using a derogatory term for gays. ((Matt Sayles/Associated Press))

American network ABC has rebuked Grey's Anatomy star Isaiah Washington overan anti-gay comment he made backstage at the Golden Globe Awards.

Washington also responded to the growing controversy over his remark, issuing a public apology on Thursday to co-star T.R. Knight, and to the gay and lesbian community.

Washington was said to haveusedthe word "faggot" in a press conference at the Golden Globes. He was denying using the term in a conflict with Knight that dated back to October. Both play surgeons on the popular hospital series.

Washington was criticized by the Gay & Lesbian Alliance Against Defamation, which wants a meeting to discuss "the destructive impact of these kinds of anti-gay slurs."

In his apology, Washington acknowledged using the term Monday night.

"I apologize to T.R., my colleagues, the fans of the show, and especially the lesbian and gay community for using a word that is unacceptable in any context or circumstance," he said.

"I can neither defend nor explain my behaviour. I can also no longer deny to myself that there are issues I obviously need to examine within my own soul, and I've asked for help."

ABC said it has "a longstanding policy to maintain respectful workplaces" for its employees, and rebuked Washington for his behaviour.

"We are greatly dismayed that Mr. Washington chose to use such inappropriate language at the Golden Globes, language that he himself deemed 'unfortunate' in his previous public apology," the network said.

With files from the Associated Press