The Metropolitan Police will include a leaflet containing homophobic comments distributed at West Ham's EFL Cup game with Chelsea on Wednesday as part of their post-match investigation.
The London Stadium fixture was marred by clashes between supporters in the closing stages, with the police making seven arrests as a result.
However, a flyer aiming to incite homophobic chanting at Chelsea captain John Terry, which spread widely on social media, will also form part of an investigation into the scenes.
A Metropolitan Police statement read: "Police are aware of a leaflet handed out before the match containing homophobic contents. This will form part of the post-match investigation."
West Ham "unreservedly" condemned the actions of sections of supporters swiftly after the game.
"We are investigating the alleged distribution of these flyers and will take the strongest possible action against those responsible," the club told the BBC.
Slaven Bilic's side won 2-1 to progess to the quarter-finals.
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