West Ham are investigating after a video emerged of a fan racially abusing Liverpool forward Mohamed Salah during Monday's 1-1 draw at London Stadium.
Egypt striker Salah, 26, was filmed on a mobile phone from a section of home supporters as he was taking a corner.
The footage, taken by a fellow fan, shows expletives directed at Salah including about his Muslim religion.
In a statement, West Ham said they have "a zero tolerance policy to any form of violent or abusive behaviour".
It continued: "We are an inclusive football club. 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."
The user who posted the video on Twitter said: "I was disgusted by what I was hearing. People like this deserve no place in our society let alone football matches."
Police are aware of the incident.
