West Ham have confirmed they are investigating claims that the families of players Victor Obinna and Frederic Piquionne were racially abused by spectators at Saturday's match against Manchester United.
Reports have suggested relatives of Obinna confronted supporters in the Main Stand at Upton Park after they and guests of Piquionne were abused.
The families were sitting in a box behind fans watching the game when they claim a small section began hurling racist abuse at them.
An altercation is understood to have taken place after at least one family member left the box to go downstairs and confront fans.
West Ham have now confirmed they are investigating the incident and will take appropriate action if required to do so.
"West Ham United are investigating the events around Saturday's match against Manchester United after allegations of racist abuse," read a club statement.
"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.
"West Ham United would like to restate the seven-point supporter plan it printed in Saturday's matchday programme and also promoted on its matchday screens around the ground."