Crystal Palace promised Sunday to ban a supporter after he was seen on video making what appears to be a racist gesture towards Tottenham's South Korean forward Son Heung-min.
The incident occurred in the 89th minute of Spurs' 1-0 win on Saturday when Son was substituted.
As the South Korea captain left the pitch at the Tottenham Hotspur Stadium, he had to walk past a section of Palace supporters, one of whom made the gesture.
"We are aware of a video circulating online (as well as reports made directly to us) regarding an individual in the away end at Spurs yesterday, appearing to make racist gestures towards Heung-min Son," said Palace in a statement.
"Evidence has been shared with the police, and when he is identified, he will face a club ban. We will not tolerate such behaviour in our club."
Tottenham said they were working with Palace and the police to identify the individual.
"Discrimination of any kind is abhorrent and has no place in society, our game and at our club," said Spurs.
Son was also racially abused during a match between Chelsea and Tottenham at Stamford Bridge in August.
Chelsea banned a season-ticket holder indefinitely after footage emerged on social media of a fan in the home end making a racist gesture towards Son in the 2-2 draw.
"We will do everything in our powers to ensure that if found guilty, the individual will receive the strongest possible action -- as was the case earlier this season when Son suffered similar racial abuse at Chelsea," said Tottenham.