Footage emerged on social media on Sunday afternoon of the group of men singing the offensive, anti-Semitic chants on a London Underground train, either before or after West Ham's 2-2 draw against fellow London club Tottenham.
As the train was travelling through Stamford Hill, a part of London well-known for it's strong Jewish community, the men were heard chanting: "I've got a foreskin, how about you? F*****g Jew."
West Ham fans filmed singing anti-semitic songs as their train goes through Stamford Hill http://t.co/9cUoOXQHVa pic.twitter.com/zHoEyDeg4V
— LBC (@LBC) February 23, 2015
The racist slur is seen as a reference not only to that particular area of London, but also to Tottenham as a club, which has strong historical connections and support within London's Jewish community.
Anti-racism group Kick It Out released a statement on Sunday after the footage emerged online. "Kick It Out has received several reports via social media about the footage and will be liaising with British Transport Police on the matter. In addition, we have been informed of a number of anti-Semitic tweets which we are reporting to the Police."
See, hear or witness discriminatory abuse? #ReportIt with our FREE app: Android (http://t.co/mzzXAkZ5kT) and iOS (http://t.co/UrAYfX8PF6)
— Kick It Out (@kickitout) February 22, 2015
The racist chanting also seems to have come despite a formal warning from West Ham officials, with a message before the match from joint-chairmen David Sullivan and David Gold warning fans not to take part in any offensive actions.
"We would also like to remind all fans attending the match at White Hart Lane that they will be acting as ambassadors for West Ham United and their behaviour should reflect the values and standards of our Club.
"Working with the Metropolitan Police, the Club will continue to adopt a zero tolerance policy towards any form of discriminatory behaviour and any fan found to be acting inappropriately — including racist, anti-Semitic and homophobic behaviour — will be punished to the full extent of the law and banned from attending matches."
The disturbing footage also comes amid the release of a good-natured joke from other West Ham fans, who posted a parody video helping a black man onto a train ahead of the team's match at Tottenham.
Does English Football Have a Racism Problem?
The latest incident has raised questions about the extent of racism in English football following last week's widely-publicised release of footage showing Chelsea supporters refusing to let a black man on to a Paris metro train and then chanting "we're racist, we're racist and that's the way we like it."
Investigations into the incident are continuing from both French and British authorities, with reports some fans continued to sing the racist chants when they arrived back in the UK, at London's St Pancras station.
A number of players, officials and pundits have spoken out against what they believe to be an engrained element of racist behaviour among some small groups of football fans.
Queen's Park Rangers (QPR) defender and former England captain Rio Ferdinand said the incident with Chelsea fans was "a rude awakening for the game."
Just for starters #WHUFC could issue statement saying they would condemn any WH fans engaging in antiSemitic chanting http://t.co/Hg4fpyqLYH
— QPR REPORT (@QPRReport) February 23, 2015
The 36-year-old was quoted in The Sun newspaper calling for more action against racism from leading football bodies FIFA and UEFA.
"We've started to think 'football has cured it' and put the whole issue on the back-burner," he said.
"For years it's been clear that FIFA and UEFA have shied away from doing what they needed to do. They have let football down, time and time again."
Meanwhile, Ferninand's boss at QPR Chris Ramsey, the English Premier League's only black manager, said he had experienced "a lot" of racism throughout his career as a player.
"Racism is not something that gets eradicated," he said. "It gets shuffled about and hidden in places you wouldn't believe."