Millwall manager Neil Harris called for anyone found guilty of racially abusing Tottenham forward Son Heung-min to be "dealt with harshly" after offensive chants were allegedly directed towards the South Korean during Sunday's FA Cup quarter-final.
Abusive comments towards Son were reportedly heard in the section of White Hart Lane housing Millwall's supporters.
Son scored a hat-trick as Spurs thrashed League One Millwall 6-0 to reach the last four.
Harris says he did not hear the alleged chants, but made his club's stance on racist abuse clear in his post-match news conference.
"I didn't hear anything," he said. "What I will say is me personally, but also the club, we won't condone that, if there is [proof].
"We came here in the right spirit, to enjoy an FA Cup quarter-final. So if that's proven to have been to the detriment to either team, and to the competition, then that is wrong. We just want people to enjoy the game.
"We want to focus on the achievement of getting here. I want people dealt with harshly.
"Mauricio [Pochettino, the Tottenham manager] will want to talk about the quality of his team and for me the focus comes away from what we've achieved. It's wrong in society and it's wrong in football."