A supporter wearing a Real Madrid shirt was escorted out of Camp Nou by Barcelona security during the Catalan giants' match against Getafe.
The fan in question tried to cover his shirt with a dark jacket, but he had already been spotted by supporters during Saturday's 2-2 draw.
According to the Daily Mail, the fan was pushed in the chest by a Barca supporter, but security personnel took control of the situation and escorted him out of the building.
Barcelona are three points behind league leaders Atletico Madrid, who suffered a 2-0 defeat to Levante on Sunday.
