The song is sung to the tune of ‘Made of Stone’, a hit for Manchester band the Stone Roses, with the lyrics instead paying tribute to Lukaku and the supposed abnormal size of his penis. It’s believed to have first been first aired at Old Trafford during United’s 3-0 Champions League win over Basel.

The inclusion organization, which works to challenge discrimination in football and is funded by the English Football Association (FA), has contacted the club to ask their supporters to stop singing a chant referencing Belgian forward Lukaku's member.

“Kick It Out is aware of footage of alleged racist chanting by supporters of Manchester United that emerged on Wednesday evening (13 September)," the organisation said in a statement, emailed to RT Sport.  

"The lyrics used in the chant are offensive and discriminatory. Racist stereotypes are never acceptable in football or wider society, irrespective of any intention to show support for a player.

"We have contacted Manchester United regarding the issue and will be working closely with them and The FA to ensure that it is addressed swiftly. If we receive any reports relating to the discriminatory chant, those will be passed on to the governing body and the perpetrators can expect to face punishment.”

The issue has split opinion on Twitter, where some fans believe the chant is an unimaginative ditty that should not be given the attention it has received, while others agree it is offensive and should be stamped out.