A man has been arrested after a complaint regarding alleged racist behaviour at Stamford Bridge on last Wednesday.
The 28-year-old man was arrested on Monday after attending a west London police station by appointment, police said in a statement.
The police statement said he was "arrested on suspicion of a racially aggravated Section 4A Public Order Act offence and currently remains in custody at the west London police station.
The arrest comes after the Blues filed a complaint to the Football Association over referee Mark Clattenburg allegedly airing a raical slur at midfielder John Obi Mikel at the weekend.
Chelsea have also promised to investigate the matter.