Real Madrid will join the complaint filed on Friday by Spanish prosecutors against Barcelona and two of the LaLiga club's ex-presidents over alleged payments to a company owned by a senior refereeing official to influence match results, the club said on Sunday.
The European and Spanish football champions called an urgent board meeting to discuss alleged attempts by arch rivals Barcelona to influence referees and decided to take legal action for what they called "serious accusations" by prosecutors.
"Real Madrid express their deep concern about the seriousness of the facts and reiterate their full confidence in the action of the justice and have agreed that, in defence of their legitimate interests, they will join the complaint as soon as the judge takes up the case," the club said in a official statement.
Barcelona allegedly paid more than 7.3 million euros ($7.8 million) between 2001 and 2018 to firms owned by Jose Maria Enriquez Negreira, who was vice-president of the refereeing committee of the Spanish football association from 1993-2018.
Prosecutors allege that under a secret agreement and "in exchange for money", Negreira favoured Barcelona "in the decisions taken by referees in the games played by the club, as well as in the results of the competitions".
A senior Barcelona official said on Friday that the club had expected the prosecutors' complaint and described it as "nothing more than an absolutely preliminary investigative hypothesis".
The official said the club "will fully cooperate with the investigation by all means necessary" and "reiterate that they have never bought any referee nor have tried to influence any official's decisions".
In a statement last month, Barca denied wrongdoing, saying they had simply paid an external consultant who supplied them with "technical reports related to professional refereeing", calling it "a common practice among professional football clubs".
The complaint focuses on the 2.9 million euros paid between 2014 and 2018 and alleges that Barcelona -- with the help of former presidents Sandro Rosell and Josep Maria Bartomeu -- reached a "confidential verbal agreement" with Negreira.
It accuses the club, Rosell, Bartomeu, Negreira and two other former Barcelona officials of corruption in sports, unfair administration and falsehood in mercantile documents.