Washington Redskins offensive tackle Trent Williams has been accused of using a racial slur at an official during Sunday’s game against the Philadelphia Eagles, according to the head of the group formed to promote diversity in hiring in the NFL. Williams denied using such a slur.

John Wooten, chairman of the Fritz Pollard Alliance, said Thursday that Williams directed the slur at umpire Roy Ellison after Ellison had attempted to stop players from both teams from directing abusive language at one another. According to Wooten, Ellison should have penalized or ejected Williams from the game but instead responded with profanity directed at Williams.

“We haven’t talked to Roy. But we are told that the players, black and white, were saying all types of things back and forth during the game,” Wooten said in a telephone interview. “Roy steps in and says, ‘Let’s stop this.’ Trent says to him, ‘[Expletive] you, N-word.’ By all rights, Roy should have thrown his flag there and said, ‘You’re gone.’ But he didn’t. He comes back at Trent with some bad language. Now Roy is wrong, too.”

Wooten said that in reaction to Williams’s alleged slur, Ellison called Williams an “ungrateful [expletive].” Wooten’s account of what Ellison said to Williams contained a different profanity than what Williams has accused Ellison of calling him.

Williams said he did not direct a racial slur at Ellison. Both Williams and Ellison are African American. “I never directed any derogatory statement toward any referee,” Williams said at Redskins Park.

“If I ever said anything like that to a ref and he feels that strongly about the word, that’s at least an unsportsmanlike [penalty]. Definitely wouldn’t just warrant a tongue-lashing from a guy that’s supposed to be the only neutral person on the field and not to feel either way about either team.

“There’s trash talk. Trash talk is trash talk. You get that in every sport."

The Fritz Pollard Alliance, which works closely with the NFL on diversity issues, said the incident — and the recent hazing and bullying controversy involving the Miami Dolphins — prompted it to issue an appeal to NFL players to stop using racially charged language.