Atletico Madrid have demanded La Liga prevent Antoine Griezmann from playing for Barcelona next season, according to the Spanish top flight's president Javier Tebas.
Griezmann confirmed he would be leaving Atleti at the end of last season, despite having only signed a five-year contract at Wanda Metropolitano in June 2018 after turning down a move to Barca.
After much speculation, Barca confirmed World Cup winner Griezmann's signing on July 12 after paying the France forward's €120 million (£107m/$134m) buy-out clause.
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However, Atleti have reported Barca to The Royal Spanish Football Federation (RFEF), who have subsequently opened an investigation into the transfer.