Arsenal have identified an image of the fan who "embarrassed" the club by throwing a bottle at Dele Alli during their defeat to Tottenham.
The club have been studying CCTV footage and are working with the Metropolitan Police to apprehend the culprit.
An Arsenal statement said: "We have all been embarrassed by the individual who threw a bottle at Dele Alli.
"We are not responsible for the actions of one individual, but send our apologies to Dele Alli and everyone at Tottenham Hotspur for this incident.
"We do not tolerate any anti-social, discriminatory or violent behaviour at Arsenal Football Club. Anyone identified will receive a lengthy club ban and their details will be passed to the police to commence legal proceedings."
Arsenal are unlikely to be punished by the Football Association for the incident.
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