Atletico Madrid are challenging Antoine Griezmann's transfer to Barcelona as they insist the Catalans should have paid €200million to activate his release clause, not €120m.
Barca confirmed the signing of Griezmann on Friday on a five-year deal after a solicitor representing the forward deposited money for his buy-out clause at LaLiga headquarters in Madrid.
However, Atletico believe the France international agreed terms with Barca before his clause dropped from €200m on July 1 and therefore claim they are owed an additional €80m to ratify the transfer.
In a statement published after Barca announced Griezmann as a new signing, Atleti said: "Atletico Madrid considers that the deposited amount is insufficient to cover his buyout clause, since it is obvious that the agreement between the player and Barcelona was closed before the clause was reduced from 200 million euros to 120 million euros.
"It was also prior to the date on which the clause was modified the communication that the player made on May 14 announcing his disassociation from the club.
"Atletico Madrid believes that the termination of the contract happened before the end of the last season due to facts, acts and demonstrations made by the player, and therefore has already initiated the procedures it has deemed appropriate to protect their rights and lawful interests."
Barca, who reportedly plan to present Griezmann at Camp Nou on Sunday, have yet to respond to Atletico's claims.