The referees' union Prospect has stepped up calls for Chelsea to apologise to Mark Clattenburg and claimed the club made a number of errors of judgment in their complaint.
Prospect national secretary Alan Leighton said the union did not intend to take legal action against Chelsea, but that the London club should feel morally obliged to make amends via an apology and compensation.
Clattenburg has been cleared by the FA of the accusation that he said "shut up you monkey" to Nigerian midfielder John Obi Mikel during Chelsea's 3-2 defeat by Manchester United on October 28, and Leighton said: "Chelsea have done a number of things wrong with this case."
He continued: "Firstly, they made the allegation and the nature on it public on the Sunday of the match.
"Secondly, on the Wednesday after their detailed investigation they decided to go ahead with a formal complaint based on one single witness statement, from one person who supposedly heard the offending phrase. The FA statement makes it clear Chelsea didn't even know when the alleged comment was supposed to have been made during the game.
"No organisation in the world would say that was ever going to get past the barrier of evidence needed to bring a charge.
"Thirdly, they have not apologised to Mark, who has gone through hell. This is about an individual who has been badly wronged and there is not even recognition about what they have done to this referee and that is staggering."
Leighton said Prospect did not want to go down the legal route.
He added: "That is not our intention at this moment. Our intention is for something to happen that avoids any need for legal action. We have been calling for Chelsea to make an apology and pay compensation because it's the right thing to do."
Sources close to Clattenburg say the referee just wants to put the nightmare of the last few weeks behind him and continue his career with the aim of being selected by FIFA for the World Cup in Brazil in 2014.