LaLiga is investigating racist abuse aimed at Real Madrid forward Vinícius Júnior during his side's 2-1 El Clásico win over Barcelona at the Olympic Stadium on Saturday.
The league have been in contact with Vinícius' camp, sources told ESPN, and is working with the police to identify the perpetrators.
"LaLiga has been working from the outset to identify the individuals involved in making racist insults and will file the relevant charges as is always the case," the league said in a statement.
"We are coordinating with the Mossos d'Esquadra [Catalan police] and FC Barcelona."
Barça said they will cooperate with the investigation.
"Barcelona will always defend the values of football and sport such as respect for the opponent and we will investigate any racist insult that may have occurred this afternoon during the match against Real Madrid," the Catalan club said in a short statement.
According to footage shared on social media, the incident appeared to happen as Vinícius was substituted at the end of the second half.
Carlo Ancelotti replaced him shortly after Jude Bellingham had scored his second goal of the game as Madrid came from a goal down to beat Barça, who had taken an early lead through Ilkay Gündogan.
The win moved Madrid back to the top of LaLiga, level on points with Girona and four clear of Barça, who remain third in the table.
Vinícius has been repeatedly targeted with racial slurs from opposition supporters in Spain, including last week when Madrid played Sevilla.
After that game, the Brazilian praised Sevilla for acting quickly after they ejected and reported a fan to authorities for racially aggravated insults.
"There's no place for racist or hateful behaviour in sport," the league said after that game. "LaLiga vehemently condemns any racist acts and will continue working to eradicate this inexcusable behaviour from our sport."
Earlier this month, Vinícius gave evidence in the trial of three Valencia fans accused of racially abusing him during a game at the end of last season.
That was one of eight incidents documented and reported by LaLiga during the 2022-23 campaign for racist abuse aimed at Vinícius.
Though the incident at Mestalla Stadium has gone to trial, in a number of cases local prosecutors opted not to press charges.