Atletico Madrid have reported Barcelona to La Liga as they continue to pursue an €80 million (£72m/$90m) addition to the transfer which has taken Antoine Griezmann to Camp Nou.
A World Cup-winning forward has completed a move from the Spanish capital to Catalunya.
Barca have paid out the €120m (£108m/$135m) required to trigger the release clause that existed in his Atletico contract.
They believe they have done nothing wrong , but domestic rivals are arguing that an agreement was reached with Griezmann when his exit fee stood at €200m (£179m/$224m).
Atletico vowed when a move was announced that they would be opening legal proceedings .
That fight has now been taken to La Liga officials and those in power at the Spanish FA (RFEF).
Atletico had been planning to take their case to FIFA, in the hope that world football’s governing body could rule in their favour.