London police launched an investigation into the racist abuse aimed towards Liverpool forward Mohamed Salah during Monday's 1-1 Premier League draw at the London Stadium.
A video emerged on social media in which audible racial slurs are directed at the 26-year-old Egypt international as he was taking a corner.
The user who posted the video on Twitter said: "I went to watch West Ham vs Liverpool and I was disgusted by what I was hearing. People like this deserve no place in our society let alone football matches."
"We are aware of a video in which it appears racial abuse is being directed at a player at a West Ham United vs Liverpool game at London Stadium on Monday, 4 February," a Metropolitan Police statement said.
"Officers are in the process of reviewing the footage. No arrests have been made and enquiries continue," it said.
"Anyone who witnesses inappropriate behaviour during a match is urged to bring it to the attention of a steward or police officer."
In a statement, a West Ham spokesman said the club have a "zero tolerance policy" to any form of violent or abusive behaviour.
"We are an inclusive football club. Regardless of age, race, religion or belief, marriage or civil partnership, pregnancy or maternity, sex, sexual orientation, gender reassignment or disability, everyone is warmly welcomed at London Stadium," he added.
"Anyone identified committing an offence will have their details passed to the police and will face a lifetime ban from London Stadium. There is no place for this kind of behaviour at our stadium."
Salah was last year named PFA Player of the Year and the Football Writers' Association's Footballer of the Year after he scored 44 goals for Liverpool in all competitions last season.
