The Metropolitan police have confirmed that they have received a complaint from someone inside White Hart Lane following the alleged antisemitic abuse that came from a section of West Ham supporters during their team's Premier League match against Tottenham on Sunday.
Spurs and West Ham have issued statements confirming that they will assist the Football Association's investigation into the alleged abuse but the matter could now become a criminal one following the intervention of the Met, with police having arrested two spectators during the match for making Nazi-style salutes, which officers described as a "racially aggravated public order offence".
Those two fans have accepted police cautions and one has been indentified by West Ham as a season ticket-holder and banned by the club. "Any other individuals identified can expect a similar swift and robust response," West Ham said.
A Met spokesman said: "We can confirm that a complaint has been received, but we are yet to speak formally with the complainant." The police are expected to meet the person who made the complaint on Wednesday but have yet to formally receive a complaint from Peter Herbert, the chairman of the Society of Black Lawyers, who said on Monday that he had reported the matter and would "meet with a borough commander of the Met Police either later this week or early next week".
Spurs' 3-1 victory on Sunday was overshadowed by West Ham supporters apparently mocking the Holocaust and chanting a song about Adolf Hitler. They were also heard singing "Viva Lazio" and "Can we stab you every week?" just three days after an attack on Tottenham fans in Rome, prior to the London club's Europa League group match against Lazio, in which one fan, Ashley Mills, was stabbed in the head and leg.
"We are currently compiling a full report for the Football Association and shall be submitting this with all our evidence including relevant CCTV footage," said a Tottenham spokesman.
A statement on West Ham's website read: "West Ham United will take the strongest possible action against any of their supporters, including enforcing life bans from the club, that are found guilty of behaviour which is categorically not condoned by West Ham United.
"During the 46 games in the Championship last season, West Ham United had zero arrests for racism or violence, so while we are surprised to see such reports today, we will examine any available evidence of such conduct thoroughly and take the appropriate action."
The FA confirmed on Monday evening that they are to look into the matter. A statement read: "The FA can confirm it has begun investigating reports of abusive chanting at the Tottenham Hotspur FC versus West Ham United FC fixture on 25 November 2011.
"The FA Governance Department has this morning contacted both clubs and will continue to make enquiries into the matter in the coming days.
"We note the statement issued by West Ham United FC and encourage Clubs to identify and ban for life any individuals involved in incidents of abusive chanting.
"There is no place for anti-Semitism or any form of discrimination in football. The FA is committed to working with the Clubs, Leagues, fans groups, the police, CPS and community stakeholders to play our part in addressing this unacceptable behaviour."
The Community Security Trust, a charity that monitors antisemitism and provides security for the UK Jewish community, has also confirmed that it has received complaints about the alleged abuse. It read: "CST has received complaints from people in the Jewish community following [alleged] antisemitic chanting by some West Ham fans at their Premier League game against Spurs yesterday.
"These include complaints from people who were at the match and others who have heard about the chants via the media.
"CST will seek to meet the Metropolitan Police, Spurs and West Ham to discuss their response to the specific problems at yesterday's match."