West Ham are investigating an allegation of racist behaviour among their supporters during Saturday's defeat to Manchester United.
A newspaper report claimed guests of Hammers players Victor Obinna and Frederic Piquionne became involved in a row with fans who shouted abuse.
A statement on the club website read: "West Ham United are investigating the events around Saturday's match against Manchester United after allegations of racist abuse.
"The club takes such matters seriously and, with the police, is reviewing CCTV footage and gathering witness information.
"Anyone found responsible will be dealt with appropriately.
"This is an isolated incident and our supporters, like the club, are proud of the positive relationship with Kick It Out - holding the Racial Equality Standard - and Show Racism the Red Card."
