Police have started an investigation after a fan made what appeared to be a racist gesture in Chelsea's League Cup win over Manchester United, reports BBC Sport. Pictures appear to show the man making a 'monkey' gesture during Wednesday's fourth-round tie at Stamford Bridge.
United striker Danny Welbeck appeared to be the target of the alleged abuse after losing possession.
Chelsea had already started their own investigation into the incident, saying they would examine the footage.
"Police have received a complaint regarding alleged racist behaviour at Stamford Bridge on Wednesday," read a Metropolitan Police statement.
"An investigation has been launched. There have been no arrests and enquiries continue."
A Chelsea spokesman said: "If we have sufficient evidence we will take the strongest possible action, including supporting criminal prosecution."
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