Real Madrid have filed a complaint with the Spanish Football Federation [RFEF] calling the referee in their 4-2 LaLiga win at Osasuna "negligent" for failing to include insulting chants aimed at Vinícius Júnior in his match report.
Television cameras picked up part of the crowd singing "Vinícius, die" during Saturday's game at El Sadar, with Madrid teammate Dani Carvajal then gesturing towards referee Juan Martinez Munuera.
Vinícius scored twice in the match and celebrated his second goal in the 64th minute by turning to the crowd and pointing at his ear.
Martinez Munuera made no mention of any offensive chanting in his formal match report.
"After the serious insults made, once again, against our player Vinícius Júnior, in this case during the last LaLiga match played by our team at El Sadar, Real Madrid C.F. communicates the following," Madrid said in a statement.
"Our club has filed a complaint with the Disciplinary Committee of the Royal Spanish Football Federation against match referee Juan Martinez Munuera, as a result of the negligent drafting of the referee's report. The referee voluntarily and deliberately omitted the insults and humiliating chants repeatedly directed towards our player Vinícius Júnior, despite being warned insistently by our players at the same time that they were occurring.
"In addition, Real Madrid has also filed a complaint with [the RFEF] in relation to the aforementioned insults and humiliating chants, and forwarded them to the State Commission against Violence, Racism, Xenophobia and Intolerance in Sports, so that those who said them are identified and punished.
"In light of the unfortunate events that occurred in El Sadar, Real Madrid has expanded the complaint that it presented last Friday, March 15, to the State Attorney General's Office against crimes of hate and discrimination, for the racist and hateful insults directed towards our player Vinícius Júnior in the vicinity of the Olympic Stadium in Montjuic and the Metropolitano Stadium in Madrid, requesting that the perpetrators be identified.
"Real Madrid once again condemns these violent attacks of racism, discrimination and hatred, and demands that the necessary measures be taken, once and for all, in order to eradicate the violence that our player Vinícius Júnior has been suffering."
Osasuna on Tuesday issued a statement strongly denying that there was any racist chanting in their stadium, while rejecting the insults "that in no case had racist references and were made by a minority" during Saturday's game.
Last week, cameras captured fans chanting "Vinícius, die" ahead of Barcelona's Champions League round-of-16 tie with Napoli at Montjuic, while a group was recorded shouting "Vinícius, chimpanzee" before Atletico Madrid's game with Inter Milan.
Vinícius has repeatedly been targeted with racist abuse from opposition fans, including at Valencia's Mestalla Stadium last May, after which an investigation was launched into three people for racially insulting the player.