Cristiano Ronaldo was heckled with homophobic abuse during last weekend's El Clasico at Camp Nou, according to Spanish media reports.
The Real Madrid hitman was mocked by Barcelona supporters throughout the contest for his close friendship with male kickboxer Badr Hari.
Barca fans were reportedly heard chanting "maricon", the Spanish slang for "faggot", at Ronaldo during a minute's silence for the late legend Johan Cruyff ahead of kickoff on Saturday.
"For months, Ronaldo has been the continuous object of insults and rumours in the tabloid and sensationalist press, and also from sports reporters, players and fans of rival teams, in order to humiliate, offend and denigrate a great football player," said Francisco Ramirez, head of the StopLGBTfobia organisation.
"It is incomprehensible that there is a double standard of intolerance in sport, and that groups act with forcefulness and unusual speed in cases of racism or xenophobia, but will continue to ignore homophobia."
La Liga has reportedly filed a complaint with Spain's State Commission against Violence in Sport over the incident, although any disciplinary measures are unlikely to follow.
Ronaldo went on to claim the winner in the closing stages of the encounter.
