Real Madrid winger Vinicius Junior was targeted with racist abuse during his side's 1-0 defeat at Real Mallorca on Sunday and La Liga are investigating the incident.
A video published by DAZN captured the sound of at least one fan calling Vinicius a "monkey".
"Once again intolerable racist insults were observed against Real Madrid player Vinicius Jr," said the Spanish top flight in a statement Monday.
"(La Liga are) working with the home club to identify those responsible, with the aim of taking the appropriate legal measures."
Spanish police are currently investigating a January incident where an effigy of Vinicius was hung from a bridge in front of the club's training ground before Real Madrid faced Atletico Madrid in the Copa del Rey.
Atletico fans were filmed chanting racist abuse at Vinicius in September 2022 but Madrid prosecutors did not press charges.
In December after being abused during a win at Real Valladolid Vinicius hit out at La Liga for continuing "to do nothing" about racists at Spanish matches.
"Racists keep going to games and watching the greatest club in the world up close and La Liga continues to do nothing," Vinicius said.
"I will carry on with my head held high and celebrating my victories and those of Madrid."
Vinicius was fouled 10 times during the clash with Mallorca and has suffered more fouls than any other player in Europe's top five leagues this season.
"I think everything that is happening and has happened is not Vini's fault, Vini just wants to play football, and beyond that, there's an atmosphere of provocation. They foul him, that is what is happening," said Real Madrid coach Carlo Ancelotti on Monday.
The coach was speaking about the tension around Vinicius during the match, before the racist abuse came to light.
"Everyone thinks that it is Vini's fault but we have to look at the game, look at what happened today with him."