Metropolitan Police are reviewing a video that appears to show a West Ham supporter directing anti-Muslim abuse at Liverpool star Mohamed Salah.
In the mobile phone footage, which circulated on social media on Wednesday, an unidentified West Ham fan can be heard insulting Salah about his Muslim faith as the Liverpool forward prepared to take a corner during Monday's 1-1 draw in the Premier League between the teams at London Stadium.
West Ham were made aware of the video by the Football Association and have launched their own investigation into the incident.
"We are aware of a video in which it appears racial abuse is being directed at a player at a West Ham vs. Liverpool game at London Stadium on Monday, Feb. 2," Metropolitan Police said in a statement issued to ESPN FC. "Officers are in the process of reviewing the footage.
"No arrests have been made and enquiries continue. Anyone who witnesses inappropriate behaviour during a match is urged to bring it to the attention of a steward or police officer."
A West Ham spokesperson added: "At West Ham United, we 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.
"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."
Kick It Out, an organisation challenging discrimination in football, issued a statement of their own.
It read: "We are dismayed to see yet another high-profile incident of discrimination in English football -- this time a video of disgraceful anti-Muslim abuse aimed at Liverpool's Mohamed Salah by a West Ham United supporter.
"We have informed the club, The FA and the UK Football Policing Unit and have offered our support to the investigation, which is already underway. We are pleased that West Ham officials have expressed their determination to identify the supporter and take firm action -- this type of behaviour is simply unacceptable and must be challenged swiftly and decisively."
The user who first posted the video to social media wrote: "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."