Barcelona will report Malaga president Abdullah Al-Thani to Spain's sports authorities for comments on Twitter.
The row began when a Barca fan asked Al-Thani on Twitter for Malaga to beat title rivals Real Madrid on 21 May.
"With the help of Allah we'll beat them on the pitch, but the scum of Catalonia will not smell the championship after telling lies about coach Michel," wrote Al-Thani in Arabic.
Malaga boss Michel upset Barca fans by hinting he wanted Real to win La Liga.
"FC Barcelona expresses its rejection and indignation at the contents of a tweet published by the president of Malaga CF, Abdullah Al-Thani, with comments which violate the principles of fair play, ethics and legality that should govern sports competition," Barcelona said in a statement.
"For this reason, the club will report this case to the anti-violence committee of the national sports council, and will refer the matter to the competition committee of the Royal Spanish Football Federation and the La Liga integrity department."
Spanish champions Barcelona and Real Madrid are level on points at the top of La Liga.
Barca lead because of a better head-to-head record with Real, who have a game in hand over their title rivals.
While Real go to 14th-placed Malaga on the final day of the league season, Barcelona are at home to Eibar - who currently sit eighth - on 21 May.
Malaga boss Michel helped Real Madrid win La Liga six times during a 14-year playing career at the Bernabeu.