Chelsea defender Antonio Rudiger has urged Tottenham Hotspur to find and punish the individuals who allegedly directed racist abuse at him during Sunday's Premier League match.
The German was involved in an incident in which Tottenham's Son Heung-min was red-carded in the 62nd minute and indicated shortly afterwards he had been the victim of a monkey gesture from the home section.
The Professional Footballers' Association (PFA) called for a government inquiry into racism in the English game following the match, which Chelsea won 2-0.
"I really hope that the offenders will be found and punished soon, and in such a modern football ground like the Tottenham Hotspur Stadium with dozens of TV and security cameras, it must be possible to find and punish them," Rudiger wrote on Twitter.
"If not, then there must have been witnesses in the stadium who saw and heard the incident. It's just such a shame that racism still exists in 2019. When will this nonsense stop?"
The FA, the country's soccer governing body, said it was working with all parties to establish facts before taking action.
"Following the incident in the match between Tottenham Hotspur and Chelsea... we're working with the match officials, the clubs and the relevant authorities to fully establish the facts and take the appropriate steps," the FA said in a statement on Twitter.
Anti-racism organisation Kick It Out applauded referee Anthony Taylor for following the racism protocol which led to repeated stadium announcements warning the fans.
Tottenham have vowed to take the "strongest possible action" if any fan is identified as having made racist gestures.
Rudiger is the latest Premier League player to suffer alleged racist abuse during a match, with Manchester United's Fred targeted by a Manchester City fan this month.
Racist incidents have tainted European soccer recently, with Inter Milan's Romelu Lukaku and Brescia's Mario Balotelli were subjected to racist insults from rival fans during Serie A matches in Italy this season.
"It's really sad to see racism again at a football match, but I think it's important to talk about it in public. If not, it'll be forgotten again in a couple of days (as always)," Rudiger added.
"I don't want to involve Tottenham as an entire club into this situation as I know that just a couple of idiots were the offenders. I got a lot of supportive messages on social media from Spurs fans as well... thank you a lot for this."