Antoine Griezmann's transfer from Atletico Madrid to Barcelona could be cancelled by La Liga, according to the Spanish top-flight's president Javier Tebas.
The France World Cup winner joined the Catalans earlier this month in a £107million deal, and his made his first appearance for them in Tuesday's 2-1 friendly defeat to Chelsea in Saitama.
But the move has been a controversial one, with Atletico accusing Barca of deliberately waiting until Griezmann's release clause lowered on July 1 before submitting a bid, even though they feel the deal was agreed before then.
"It is possible to block a player's transfer," Tebas told Spanish radio station Onda Cero .
"La Liga will have to decide what course of action to take."
Elaborating on the Atletico's desire to pursue the cancellation of the deal, Tebas said: "[Atletico] submitted a complaint and put in doubt whether we should pass Griezmann's licence to Barcelona .
"There's a process that has been put in motion and those overseeing it will have to come to resolve the case."
Griezmann was said to be close to joining Barca last summer only to announce that he was staying at Atletico in a video he posted on social media called 'The Decision', which didn't go down well with Barca fans and some board members.
He then announced he would be leaving the club earlier this summer.
Barca technical secretary Eric Abidal insists that it was only after that announcement that Barca made their move.
"Atletico Madrid are defending their interests and so do we at Barcelona," the former defender told Le Parisien, via Marca .
"In no way did we have any prior agreement with the player.
"[Barcelona] got in touch with his entourage, including his lawyer, after Griezmann announced his intention to leave his former club.
"[Barcelona] president Bartomeu contacted Atletico to learn about Griezmann's contractual conditions and to inform them that, if there was to be no negotiations, Barcelona would pay the release clause of 120 million euros.
