United won the contest 3-1 at Old Trafford to reach the fourth round at the expense of its fellow Premier League side.

A section of home supporters were heard using homophobic language, with the chant thought to be aimed at Everton manager Frank Lampard.

The FA released a statement after the match confirming it is investigating the matter.

"We continue to work closely with the Crown Prosecution Service, as well as the UK Football Policing Unit, in relation to the use of this term," the statement read. 

"Part of our work in this area has been to provide the relevant authorities with impact statements from LGBTQ+ supporters, detailing how chants of this nature affects their experience and feeling of inclusion at football matches, so that a clearer stance and understanding on the chant can be established.

"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."

Conor Coady levelled up for Everton after Antony's early strike but the defender then put into his own net prior to Marcus Rashford's late penalty sealing progression for United.

In a widely released statement of its own, United also condemned the chanting from its supporters.

"Homophobia, like all forms of discrimination, has no place in football," the statement read. "Manchester United is proud of our diverse fan base and the work we have done to reduce instances like we sadly heard today.

"We will continue to campaign for inclusivity and to tackle discriminatory abuse whether inside stadiums or online. This includes working with fan groups to educate fans on the offence which discriminatory language causes."

The incident comes less than a week on from Nottingham Forest launching an investigation into allegations of homophobic chanting directed at Chelsea fans in a 1-1 draw.