Jose Mourinho has been charged with misconduct by the Football Association for suggesting that referees have been influenced by a "campaign against Chelsea".
The Portuguese coach made the comments following the Blues' 1-1 draw with Southampton on December 28.
During the clash, Cesc Fabregas was booked by referee Anthony Taylor for diving, despite appearing to be fouled in the penalty area by Southampton's Matt Targett.
After looking over Mourinho's comments, the FA has released a statement saying: "It is alleged his remarks constitute improper conduct in that they allege and/or imply bias on the part of a referee or referees and/or bring the game into disrepute."
The 51-year-old has also been given a formal warning by the governing body for comments that he made on December 19 prior to Chelsea's 2-0 win over Stoke City.
Mourinho has until 6pm on January 13 to respond to the misconduct charge.