Tottenham say the London Metropolitan Police has been unable to find any evidence to corroborate or contradict Chelsea defender Antonio Rudiger's claim of racism.
Rudiger complained that he was subjected to monkey chants in his side's 2-0 win at Spurs on 22 December , but an "extensive" investigation, using CCTV and lip readers, has been unable to identify any perpetrators.
As a result the police have closed the case.
Spurs said in a statement: "The police have notified us today that, having reviewed and investigated, they have closed the crime report as they can find no evidence to support the allegation of racial abuse."
Rudiger told his captain Cesar Azpilicueta that he had been abused shortly after his role in Son Heung-min's red card in the pre-Christmas fixture.
Spurs responded swiftly, launching a full investigation alongside the police.
The statement added: "The club and the Metropolitan Police have now exhausted all avenues of investigation following the reported incident at our home fixture against Chelsea on 22 December.
"We carried out extensive reviews of CCTV images and footage, working with professional lip readers.
"All materials and reports have now also been reviewed by the police who have carried out their own investigation."
The statement concluded: "We fully support Antonio Rudiger with the action that he took - however there is no evidence to corroborate or contradict the allegation and as such neither ourselves nor the police are in a position to take any further action.
"We are fiercely proud of our anti-racism work and our zero tolerance of any form of discrimination.
"This is one reason why we have attributed so much time and resource to investigating this matter. Had we identified anyone guilty of this we were intent on issuing them with a lifetime ban from our stadium as they would have no place among our proud, diverse fan base.
"If any new information comes to light, this will be fully investigated."