The newspaper that published the staggering details about Lionel Messi’s contract Sunday is set to face legal action.

Barcelona, who claim to have had no involvement in the leak, plan to sue Spanish publication El Mundo for releasing details about the Argentine superstar’s record-breaking four-year, €555-million deal signed in 2017.

“In view of the information published today in the newspaper El Mundo, in relation to the professional contract signed between FC Barcelona and the player Lionel Messi, the club regrets its publication given that it is a private document governed by the principle of confidentiality between the parties,” the club said in a statement.

“FC Barcelona categorically denies any responsibility for the publication of this document, and will take appropriate legal action against the newspaper El Mundo, for any damage that may be caused as a result of this publication.

“FC Barcelona expresses its absolute support for Lionel Messi, especially in the face of any attempt to discredit his image, and to damage his relationship with the entity where he has worked to become the best player in the world and in football history.”

Messi responded to Sunday’s bombshell by alerting his legal team to also take action against the outlet and to investigate whether any Barcelona officials played a role in leaking the document to the media, Sam Marsden and Moises Llorens of ESPN FC report.

It’s reported that only four copies of the contract, believed to be the most lucrative deal that an athlete has ever signed, are known to exist.

Along with releasing the full sum of Messi’s contract, El Mundo also revealed the 33-year-old earns around €72 million annually. He can earn more through add-ons, which include playing in 60% of Barcelona’s games, progressing in the Champions League, and other incentives.

But, considering Messi agreed to take a pay cut last summer in response to the COVID-19 pandemic, his earnings are expected to fall short of €555 million when his contract expires at the end of June.

Messi’s future at the club beyond this season remains very much in the air, as the six-time Ballon d’Or winner failed to engineer an exit last summer and decided to stay another year in order to avoid a legal battle with Barcelona.