Real Madrid have filed a complaint against the referee who took charge of Saturday's win at Osasuna for omitting alleged racist abuse towards forward Vinicius Jr from his match report.
The club say the "insults and vexatious shouts" were "deliberately" not included by Juan Martinez Munuera.
Osasuna have denied there were any racist chants from their fans.
Vinicius has been targeted by racist abuse on multiple occasions in Spain over the past three years.
Real have demanded "necessary measures be taken" to "eradicate" the abuse.
The Spanish Football Federation's technical committee of referees has been contacted for comment.
Real said: "The referee voluntarily and deliberately omitted the insults and vexatious shouts directed repeatedly towards our player Vinicius Jr, despite these being insistently pointed out by our players at the very moment when they were taking place.
"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, to eradicate the violence that our player Vinicius Junior has been suffering."
The 23-year-old scored twice in a 4-2 win that moved Real Madrid 10 points clear at the top of La Liga.
Osasuna acknowledged that a minority of their fans aimed insults at Real players but insisted they "had no racist references".
"Given the information published in the media after Real Madrid's press release, which presents El Sadar [stadium] with racist behaviour, Osasuna wants to clarify that no racist chants were uttered [during] Saturday's match," Osasuna said.
"The club will not tolerate the tarnishing of the reputation of the Osasuna fans, who, throughout its history, have been known for their anti-racist stance."
Real Madrid have also added the incident to a complaint initially filed to Spanish legal authorities on Friday over alleged racist insults towards Vinicius by Atletico Madrid and Barcelona fans.
A video on social media appears to show Atletico Madrid fans chanting a racist slur before their Champions League game with Inter Milan on Wednesday, while Real allege there were similar chants from Barcelona fans before their encounter against Napoli the previous day.
The Brazil international has endured numerous instances of racist abuse in recent seasons.
They include Real's derby win away over Atletico in September 2022, when Atletico condemned "unacceptable" chants by a "minority" of fans towards Vinicius outside their stadium before the game.
Last June, four men were fined 60,001 euros (£51,700) and given a two-year stadium ban for hanging an effigy of Vinicius near Real's training ground in January 2023.
On the same day, three other people were fined 5,000 euros (£4,300) and banned for one year for making racist gestures during Real's game at Valencia last May.
This season there have been reports of more racist abuse towards Vinicius as Real played at Sevilla in October, at Barcelona the following week and at Valencia earlier this month.
Source BBC
BDST: 1024 HRS, MAR 20, 2024
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