Video footage has emerged of a group of men, thought to be West Ham fans, chanting anti-Semitic abuse on a train in north London.
Anti-discrimination group Kick It Out has contacted police over the footage, filmed on Sunday.
The video appeared on social media showing fans on the way to the 2-2 draw with Tottenham at White Hart Lane.
West Ham said it had a “zero-tolerance policy” and perpetrators could be banned from the club’s ground for life.
It had warned fans before the match that “any form of discriminatory behaviour” would not be tolerated.
Most Spurs fans are not Jewish but the club has a historical association with London’s Jewish community.
The latest controversy comes after Chelsea supporters were filmed pushing a black man from a train on the Paris Metro last week.
Source: BBC News