Tottenham have employed lip readers to study crowd footage after Chelsea defender Antonio Rudiger alleged he had been subjected to racist abuse.
In Sunday's Premier League match between the two clubs, play was halted at the Tottenham Hotspur Stadium while announcements reminded fans there is "no place for racism in the game".
During the match, Rudiger appeared to signal he had been subjected to monkey chants from supporters.
Meanwhile, a Chelsea fan was ejected from the ground and arrested for allegedly committing a racially aggravated public order offence against Tottenham's Son Heung-min.
The Metropolitan Police have made a total of six arrests, including one for a racially aggravated public order offence, but none were directly linked to the incident involving Rudiger.
The force is continuing to investigate the alleged racist chanting from Tottenham supporters.
"Officers will work with the club in an attempt to identify any people responsible," a Scotland Yard spokesman said.
Rudiger stated after the game - won 2-0 by Chelsea - that "it is really sad to see racism again at a football match" and put the blame on "a couple of idiots".
He was involved in an incident that led to Son being shown a red card in the 62nd minute, prior to his allegation of being racially abused.
On Monday afternoon, Tottenham issued a statement to provide an update on the alleged abuse of Rudiger as they described how the findings of their investigation had so far been "inconclusive".
"We are able to track every fan via the cameras and have spent many hours reviewing CCTV footage," the statement said.
"We have engaged lip readers to study the footage and contacted Chelsea for further information from their players.
"We have also taken statements from other parties present at the time. The police will be reviewing our evidence alongside us.
"Please be assured we shall be exhaustively investigating this matter.
"This club has a proud track record of anti-racism work across all our communities and we are determined to ensure that we conduct a thorough investigation.
"Any fan found to be guilty will receive a lifetime ban.
"At this time however we should point out that our findings are inconclusive and would ask that comment is reserved until the facts are established."
Tottenham also called for further clarity from the Premier League over which anti-racism protocols should be employed during matches.
Three announcements about racist behaviour were made to the crowd during Sunday's game, which Tottenham said had "created a misconception that any issue was ongoing".
Their statement added: "In respect of protocols - when the incident was conveyed to the referee Anthony Taylor, he took the decision to call for the implementation of stage 1 of the UEFA protocol - rather than the Premier League protocol - and asked for an announcement to be made, as well as requesting a further announcement which created a misconception that any issue was ongoing.
"The Premier League protocol differs from UEFA protocol in that it does not call for an announcement rather that the individual(s) be dealt with by the safety team in the first instance.
"We have asked that the Premier League clarifies the position regarding the use of these protocols to all stakeholders going forward."
The Professional Footballers' Association said it was "dismayed and disgusted" after Sunday's match and called for a government inquiry into racism and the rise in hate crime in football.
Sports minister Nigel Adams was due to meet with Tottenham on Monday.
Prime Minister Boris Johnson's official spokesman said the government would be monitoring the authorities' response and is ready to take further steps if required.
Tottenham have asked anyone with further information to email the club on firstname.lastname@example.org or text 07537 404821.