Osasuna have denied that there were any racist chants from their fans during the 4-2 home defeat by Real Madrid last weekend, the LaLiga club said in a statement on Tuesday.
Real Madrid have filed a complaint against the referee who handled Saturday's game at El Sadar stadium for not including in his match report alleged insults aimed at their Brazilian forward Vinicius Jr, the capital club said on Monday.
"Given the information published in the media after Real Madrid's press release, which presents El Sadar 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."
Osasuna acknowledged that a small number of their fans insulted Real players and condemned the behaviour.
"In addition, Osasuna wants to show its rejection of the insults - which had no racist references - that a minority proffered last Saturday at El Sadar," they added.
"The club rejects these chants that, unfortunately, its players also have to suffer when they visit other LaLiga stadiums."
The RFEF's Technical Committee of Referees (CTA) supported the match official and said Real Madrid's accusations were "unfair".
"(CTA) wants to express its total and unconditional support for the First Division referee Mr. Juan Martinez Munuera, following the unfair accusations made by Real Madrid CF in their complaint to the Competition Committee," the CTA said on Tuesday.
"The aforementioned club alludes to a series of warnings made by its players about shouts or chants by the public against the player number seven of their club.
"We must clarify that, once the audios of the match were reviewed, no indication was heard from any Real Madrid CF player regarding this issue nor, after the match, did the club delegate inform the referee of any incident related to these shouts or chants."
Reuters has contacted Real for comment on the CTA statement.
The Committee added that the referee did reflect in his report the incidents that he considered significant, "fulfilling his duties (...) in the fight against violence, racism and xenophobia".
A reference to abusive chants aimed at Vinicius in the first half of the match was included in a separate incident report compiled by the CTA, a copy of which was attached to the CTA's statement.