The ongoing feud over what was or was not said in the heat of an on-set argument between the stars of hit US drama Grey’s Anatomy shows no sign of dying down.

GLAAD, the Gay and Lesbian Alliance Against Defamation, are demanding that actor Isaiah Washington apologise for using the word ‘faggot’ when he denied calling co-star TR Knight a faggot on set.

Reporters were surprised when Washington, in the press room after the Golden Globes award ceremony on Monday night, said that he had never called his fellow actor a faggot during the alleged on-set altercation.

In October last year, Washington released a statement through his agent saying, “I sincerely regret my actions and the unfortunate use of words during the recent incident on set.”

Now GLAAD have slammed the African-American for repeating the offensive word in front of the press.

President Neil Giuliano says, “When Isaiah Washington uses this kind of anti-gay slur – whether on set or in front of the press – it does more than create a hostile environment for his castmates and the crew of Grey’s Anatomy.

“It also feeds a climate of hatred and intolerance that contributes to putting our community in harm’s way.

“Washington’s repeated use of it on-set and in the media is simply inexcusable.”

“We want to sit down with him and give him an opportunity to raise public awareness about the destructive impact of these kinds of anti-gay slurs.”

Rumours of his alleged on-set abuse of co-star TR Knight leaked last October, and the pressure led Knight to come out of the closet.

Earlier in the week another star of Grey’s Anatomy attacked Washington’s public denials that he used homophobic language.

“I’m going to be really honest right now, he needs to just not speak in public. Period,” Katherine Heigl told Access Hollywood at a Golden Globe after-party.

“I’m sorry, that did not need to be said. I’m not OK with it.”

GLAAD president Giuliano commented, “over the past four months Washington has become part of a significant problem of anti-gay prejudice in this country. He now has an opportunity to be part of the solution.”