Tottenham are “conducting a thorough investigation” into allegations of racism during Sunday’s match against Chelsea, and have vowed in a statement to take the “strongest possible action”.

There was a stadium announcement after 75 minutes saying that “racist behaviour among spectators is interfering with the game”.

Stills from Sky Sports of Chelsea defender Antonio Rudiger appeared to suggest he was claiming a fan made a monkey gesture towards him.

Chelsea captain Cesar Azpilicueta explained the series of events around Rudiger’s reports of racist chanting.

He told Sky Sports: “We have meetings with the Premier League before every game and we have been told to report straight away to the referee if any incident of racism happens.

“Toni came to me and told me he heard some racist songs toward him, so I reported to the ref immediately and left it to the ref to do his job.

“We are very concerned and very aware of this behaviour and we need to stop it. Now I hope everything gets clear and we eradicate it as soon as possible.

“It’s an issue not only in football but in life and all together we need to work towards the eradication of the problem.”

Mourinho expressed little knowledge of the racism incident, preferring to leave referee Anthony Taylor and his colleagues to follow the set protocol for such situations.

“I saw nothing,” he said. “I saw the referee following the protocol, I saw the referee speaking with (fourth official Andre) Marriner, I saw the referee coming to me and to Lampard and tell us what was going on, and the protocol was followed.

“Every club is together on this situation and of course we are disappointed.”

Former England defender Ashley Cole admitted he had “a lot of abuse” from the stands during his time as a player.

“You try to block it out, but obviously he (Rudiger) has heard something,” Cole said on Sky Sports.

“Players keep going to the referee, but we see the same things happening.

“These people need educating. In society it is easy to say what you want on social media, you don’t see their faces.

“People around them need to be grassing them up, getting them thrown out and banned.”

Like Mourinho, Chelsea boss Frank Lampard was reluctant to get too deeply involved in discussion of the abuse allegedly aimed at Rudiger.

“My understanding is there was a racist comment or gesture,” he said. “I haven’t spoken fully to Toni about it but I know they’re speaking to the officials as they should do.

“From our point of view, whether it’s at Stamford Bridge or here or any stadium, we would absolutely want the right procedure in because we don’t want to see that sort of stuff.

“We’ll leave that to them to get on with.” 

Anti-racism organisation Kick it Out later released a statement on Twitter.

It read: “We are aware of the alleged racist incidents at today’s game between Tottenham Hotspur and Chelsea.

“We applaud the reaction of referee Anthony Taylor in following step one of the protocol and the ensuing steps taken by Tottenham Hotspur in repeating the stadium announcements.

“We have offered our support to both of the clubs and also to Chelsea’s Antonio Rudiger.”