Spanish police arrested seven people on Tuesday over two incidents of racial abuse targeting Real Madrid's Brazilian star Vinicius Junior, including one this weekend that sparked an international outcry.

Spain's football league, La Liga, has been engulfed in a racism scandal after the 22-year-old forward was subjected to racist taunts during Sunday's 1-0 defeat at Valencia and later sent off.

The player has been taunted by opposition fans since he joined Real in 2018 but the latest incident has kicked up a storm over whether Spain is doing enough to stamp out racism in football.

Early on Tuesday, police confirmed arresting three youths in Valencia for "insults and gestures with racist overtones" towards the player that amounted to "an alleged hate crime" during Sunday's match.

The game was held up for several minutes and the referee wrote in his post-match report that shouts of "monkey" had been directed at Vinicius.

Police said the investigation remained open to identify further suspects.

In a statement, Valencia confirmed three fans had been arrested, reiterating its "strongest condemnation against racism and violence" and saying the club was acting against those involved "by banning them for life from our stadium".

Also on Tuesday, Madrid police arrested another four men suspected of hanging an effigy wearing a Real Madrid shirt with Vinicius' number on it from a bridge in January.

The dummy was hung by the neck from a highway bridge near Real Madrid's training ground on January 26 ahead of their match against Atletico Madrid.

Above it was a banner in Atletico's red and white reading: "Madrid hates Real." (AFP)