The Metropolitan Police has dropped an investigation into alleged comments by referee Mark Clattenburg towards Chelsea's John Obi Mikel and Juan Mata.
Police said there was no evidence an offence was committed during Manchester United's 3-2 win over Chelsea.
The Football Association launched its own investigation that will continue and Chelsea made an official complaint to the FA that solely concerned Mikel.
Clattenburg has always denied the allegation he used racial words.
Chelsea's complaint came after the police had already begun its investigation and followed a thorough investigation, which they claimed was led by outside legal counsel and used information from interviews with club players and staff.
Police said in a statement on Tuesday: "Inquiries were made and no victims have come forward. The matter will remain as a recorded incident.
"Without a victim and/or any evidence that any offence has been committed, the matter cannot currently be investigated.
"If the situation changes and a victim and/or evidence to support an allegation of a crime comes to police attention, then further inquiries will, if appropriate, be made."
Earlier on Tuesday, Chelsea chairman Bruce Buck insisted the club are not hypocrites for supporting skipper John Terry while lodging a complaint against Clattenburg.
Buck said Chelsea have a "duty of care" towards Terry even though he was banned for four matches for racially abusing QPR's Anton Ferdinand.
Buck told London's Evening Standard newspaper: "Suppose we had tried to sweep this under the rug and said to the various players, 'Look, it's not a big deal and the press are going to be all over us, maybe you want to reconsider'. If that had leaked out, we would've really been crucified."
Police started their probe after a complaint from outside the game.
The Football Association is expected to announce the outcome of its investigation on Friday.
The governing body has spoken to Clattenburg, along with assistant referees Michael McDonough and Simon Long and fourth official Michael Jones, who were on duty with him at Stamford Bridge.
It is believed all the other officials, who were wired up together with Clattenburg, have said they did not hear any use of the racial terms alleged by Chelsea.
FA officials are keen to ensure a swift conclusion to the case, which follows the recent four-match ban handed to Terry for racist abuse.
Clattenburg returned to training with the Select Group of referees on Monday for the first time since the start of the investigations.
But he will not take charge of a top-flight match this weekend, having been omitted from the list of match officials for the third straight week in the list issued by the Premier League.
The 37-year-old is viewed by the Professional Game Match Officials, the referees' organisation, as one of the leading officials in the country.
He regularly referees games in European competitions and was put in charge of the League Cup final in February and the Olympic final between Brazil and Mexico in August.