The banner, which read “Sordell is a c***”, related to complaints made by Sordell after he was abused by fans while warming up for a match on October 6, leading to a 13-year-old boy being banned from Millwall’s ground.

A Metropolitan Police spokesman said six men were arrested on suspicion of public order offences and have been bailed until early December.

The banner on display was swiftly removed by Millwall staff.

The club has so far refused to comment on the issue, and assistant manager Joe Gallen – standing in for Lions manager Kenny Jackett, who missed the game with flu – also opted not to discuss the matter.

Sordell took to Twitter after the Millwall match last month to claim that he and team-mates Lee Chung-yong, Darren Pratley and Benik Afobe were subjected to racist taunts.

That sparked an investigation led by both clubs and last week Millwall confirmed the boy in question admitted to abusing Sordell and subsequently issued a written apology which the player accepted.

Given his age, Millwall have not imposed a life ban on the youngster and offered him a place on a “Millwall for All” educational programme “in the hope that we can change his outlook on equality, racism and life in general”.