Watford are continuing with their complaint over Everton’s pursuit of Marco Silva.
Vicarage Road cited the Blues’ interest in Silva as an ‘unwarranted approach’ which was a factor in their decision to part with him in mid-January.
Relations between the two clubs appeared to have improved with winger Richarlison finalising a £35 million move from the Hornets on Tuesday.
However Watford insists that they are continuing to pursue their case against Everton, who appointed the Portuguese coach at the end of last season.
“The club have made an official complaint to the Premier League over an allegation of an illegal approach to former manager, Marco Silva,” read a club statement.
“The complaint to the Premier League makes clear the seriousness of the allegation and what the club believes is overwhelming evidence of a clear breach of Premier League rules.
“At the request of the Premier League we entered into mediation with Everton in a process that involved club officials and their respective legal teams, with no conclusion being reached.
“Therefore the disciplinary process continues. In pursuing its disciplinary claim, the club has known from the outset it forfeited any right to compensation as a consequence of not following a proposed arbitration process.
“We believe this situation is not about a compensation figure but the principle of making a stand when the actions of one Premier League club completely undermine and cause intrinsic damage to a fellow member club.
“We trust in the Premier League to fully investigate the complaint and we will comply with that process.”