Man United have been urged to ban a Romelu Lukaku chant branded "racist" by fans and campaigners.
The new song has been heard on several occasions since Lukaku's £90million move from Everton this summer.
Sung to the tune of 'Made of Stone' by the Stone Roses, the lyrics make reference to the striker being well-endowed.
Scott Patterson, who publishes the popular blog The Republik of Mancunia, slammed the chant as "drivel that belongs in the 1980s."
He went on: "Here we have a hugely talented striker, currently the top scorer in the league, yet he’s reduced to us celebrating the supposed size of his d***.
"It’s a cheap and insulting stereotype that has no place in this day and age."
The anti-discriminatory group Kick It Out called the chant "offensive".
The issue now been raised with both Manchester United and the FA.
"Kick It Out is aware of footage of alleged racist chanting by supporters of Manchester United that emerged on Wednesday evening, " spokesman told The Times.
"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 issues and will be working closely with them and the FA to ensure that it is addressed swiftly.
"If we received any reports relating to the discriminatory chant, those well be passed to the governing body and the perpetrators can expect to face punishment."
A similar debate cropped up in 2011 when Spurs fans were urged not to sing a chant about Emmanuel Adebayor.
The club conceded it was offensive in nature, but not racist.
Kick It Out condemned the song saying it had "racial undertones" and the player himself appeared upset by it.
"Big players better than me have tried to stop that, but it's not easy at all. We have done everything we can to show the red card to racism," he said.
"But people are still into it, that's part of life."