Investigating judge Joaquin Aguirre Lopez said he believed that any other LaLiga team that competed against Barcelona between 2001 and 2018 - when the club made alleged payments to a company owned by a senior refereeing official - may have been harmed by the alleged scheme and could take legal action.

In March, prosecutors filed a complaint over alleged payments of more than 7.3 million euros over 17 years to firms owned by Jose Maria Enriquez Negreira, who was vice-president of the football federation's refereeing committee (CTA) from 1993 to 2018.

Barca's arch-rivals Real Madrid had joined the prosecution in the lawsuit as a damaged party.

"It is presumed by pure logic that FC Barcelona would not pay vice-president Negreira around 7 million euros since 2001 if they were not benefited by him," Aguirre said in Tuesday's ruling rejecting Barca's appeal against Real Madrid's participation in the complaint.

Other first-division teams could potentially have been harmed as well, he said, if proven that the CTA assigned referees to certain matches according to criteria unrelated to their technical qualities.

Reuters has been unable to reach Negreira. Barcelona and Real Madrid were not immediately available for comment.

"In any case, we are facing a novel form of possible illegitimate retribution for football referees," he added.

According to the judge, Negreira was responsible for ranking and evaluating the referees. However, no evidence has been found so far of Negreira paying referees to influence match results, Aguirre said.

The court also opened a separate case to investigate alleged money laundering by Negreira, his son and the network of companies through which Barcelona's alleged payments were made.

In a statement in February, Barcelona denied any wrongdoing, saying it had paid an external consultant who supplied it with "technical reports related to professional refereeing". It was a common practice among professional football clubs, they said.