Atlético Madrid have reported Barcelona to Fifa for making an illegal approach for their France striker Antoine Griezmann.

Griezmann, who signed a contract with Atlético in the summer lasting until 2021 to ward off interest from Manchester United, has been the subject of increased speculation over recent days after Barça’s director of institutional relations hinted it was “possible” the club’s president, Josep Maria Bartomeu, had held talks with the 26-year-old’s family.

Fifa’s rules say a team interested in signing a player must first make contact with his club before being allowed to hold negotiations.

“Atlético Madrid have reported Barcelona for repeated contact with Griezmann and his people, contact which we are aware of,” a spokesman for Atlético told Mundo Deportivo. “He is a player with a contract with Atlético Madrid and a long contract at that.”

Griezmann has a release clause in his contract set at €100m (£88.4m) but Barcelona have been linked with a January approach for the forward signed from Real Sociedad in 2014. A report last week suggested Barça’s technical director, Roberto Fernández, had already held talks with the Frenchman’s entourage, with Guillermo Amor later admitting the club are interested in signing him.

“If that’s what the newspaper said, it’s possible …” Amor told Movistar+. “Maybe there’s been a meeting and things have advanced, although I don’t know. There’s a good understanding, maybe there have been talks. “Rumours are inevitable in football. In the case of Griezmann, there are a lot of players we could be talking with, initiating some kind of relationship if there’s an opportunity. We’re obliged to have contact with players. It’s something which is done.”

Unbeaten Atlético are second in La Liga, six points behind the leaders Barcelona and their spokesman also suggested any approach for Griezmann “may violate the current competition of La Liga in which both teams are now in the first and second positions of the table fighting for the same prize.”Fifa has since confirmed it has received Atlético’s complaint.