Atleti finished their remarks with two further, more serious, points.

"Remember, it took us just five minutes to create this fake post. We live in an era where reality can be altered. Don't believe everything you see, especially if it's related to Barca."

In a further post, the club added: "In recent months, we've been suffering a smear campaign against one of our players.

"Leaked information with ulterior motives, 'fake news', constant disrespect, the culé version of the propaganda machine inventing little stories, calls before direct match-ups.

"But of course, it wouldn't occur to us either to have the referees' vice-president on our payroll or to resort to political favours to register players. RESPECT and VALUES."

That referred to alleged payments Barcelona made to Jose Maria Enriquez Negreira, the former vice-president of Spain's referees' committee. That investigation is ongoing and Los Cules have denied any wrongdoing.

It is not the first time the two clubs have clashed over a player.

In 2019, Barca were accused of disrespect by Atleti in their efforts to sign Antoine Griezmann.

The French forward did move to the Nou Camp but rejoined Diego Simeone's side - initially on loan - two years later. The 35-year-old is set to join Major League Soccer side Orlando City this summer.

Alvarez, who has scored 20 goals in all competitions this season, joined Atleti in 2024 from Manchester City in a deal worth up to £81.5m.