Police launch hunt for 'racist' Chelsea fan November 1, 2012 -- Updated 1831 GMT (0231 HKT) Manchester United's Danny Welbeck, right, appeared to be the target of alleged racist abuse during his side's defeat at Chelsea. Police launch investigation into allegations of "racist gesture" by Chelsea supporter Supporter photographed in British national newspaper making alleged gesture Manchester United striker Danny Welbeck appeared to be the target of alleged abuse Chelsea promise to "take the strongest possible action, including criminal prosecution" (CNN) -- English football's battle to eradicate racism suffered another blow on Thursday as police launched an investigation into allegations that a Chelsea supporter made a racist gesture towards a Manchester United player. A photo of the fan making a "monkey" action, which appeared to be targeted at United's Danny Welbeck during a League Cup match that Chelsea won 5-4, was published in a British newspaper Thursday Chelsea has launched its own investigation into the matter and has already promised to assist the police in any way possible. A statement from the Metropolitan Police read: "Today, Thursday, November 1, police have received a complaint regarding alleged racist behavior at Stamford Bridge last night, Wednesday, October 31. An investigation has been launched. There have been no arrests and enquiries continue. The Macedonia FA were fined $26,000 after fans racially abused England trio Ashley Cole, Sol Campbell and Emile Heskey during a qualifying game for Euro 2004. The Croatian FA were ordered to pay a $16,000 fine after their fans were found guilty of "displaying a racist banner and showing racist conduct during the Euro 2008 quarter-final tie against Turkey. Russia were again in the news for the wrong reasons at Euro 2012 and were fined $39,00 for "the setting off and throwing of fireworks by Russia spectators, displaying of illicit banners and the invasion of the pitch by a supporter," during the Euro 2012 tie against Poland. Russia was also fined $155,000 after clashes between supporters and police during and after their game against the Czech Republic. Porto were hit by a $27,000 fine after their fans were found guilty of subjecting Manchester City forward Mario Balotelli to monkey chants during a Europa League game in February 2012. It took UEFA six weeks to finally hand out a punishment. But questions were raised after UEFA also fined City $40,000 after the club were found guilty of coming back out on to the field of play late after the halftime interval. Serbia scuffles Macedonia punished Trouble in Bulgaria Russian FA hit with fine Croatia in the dock Crackdown on Russia Bendtner loses gamble Porto punished Walter Tull Tottenham's Tull Fatally wounded at Favreuil Center stage Rose's outrage Serbia scuffle Roberts' refusal Black footballers' association The first black international The incident follows Chelsea's claim that a referee made racial comments to one of the club's players during Sunday's 3-2 home defeat by United -- a controversial match in which the Premier League-leading team had two men sent off. Chelsea lodge Clattenburg complaint On Wednesday, Chelsea confirmed it had lodged a formal complaint with the Football Association after alleging that official Mark Clattenburg had used "inappropriate language towards John Obi Mikel. Now the club has stated that it will take "the strongest possible action" against the supporter involved in Wednesday's incident. "Chelsea Football Club can confirm we are investigating an incident involving a member of the crowd at last night's game against Manchester United," a spokesman said. The club will be examining all available footage and asks anyone who can identify the individual to contact the club. Chelsea FC is committed to removing all forms of discrimination and if we have sufficient evidence we will take the strongest possible action, including supporting criminal prosecution. Police to investigate 'racist' referee in Chelsea case Chelsea banned a supporter for life in March after finding them guilty of racially abusing the club's former striker Didier Drogba. Club captain John Terry is currently serving a four-match domestic suspension after the FA found him guilty of racially abusing Queens Park Rangers defender Anton Ferdinand despite the former England international having been earlier cleared in court.