England's Football Association (FA) will investigate alleged anti-gay chanting during Everton's 3-1 FA Cup third round loss at Manchester United on Friday.
Some supporters were heard using anti-gay language against Everton manager Frank Lampard, who previously played for and managed Chelsea, British media reports said.
"We stand firmly against all forms of discrimination and we are striving to ensure our game is a safe environment for all, which truly embraces diversity and challenges hateful conduct both on and off the pitch," an FA spokesperson said.
In a statement to British media, United said, "homophobia, like all forms of discrimination, has no place in football.