Barcelona said on Sunday they could take legal action against Spanish newspaper El Mundo after it published details of Lionel Messi's contract with the Spanish top club.
"The club regrets its publication given that it’s 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 the appropriate legal action against the newspaper El Mundo, for any damage that may be caused as a result."
El Mundo carried the details of Messi's contract in its Sunday edition, breaking down the amount of money the 33-year-old player would have earned from a four-year deal he signed in November 2017: 555.237.629 euros before taxes.
The information revealed by El Mundo has made world news.
Various Spanish media outlets reported Sunday that Messi is also considering taking legal action against El Mundo.
'No future at the club'
Barcelona coach Ronald Koeman defended Messi in comments on Sunday after the team's match against Athletic.
"What has come out is intended to damage him. Messi deserves respect," Koeman said.
"He has done so much for Spanish football. There are people out to hurt Barcelona and Messi. If it turns out to be someone on the inside then that is very bad and they should have no future at the club."