London - Millwall manager Neil Harris called for strong action to be taken against fans who allegedly chanted racist abuse at Tottenham forward Son Heung-Min during Sunday's FA Cup quarter-final.
South Korea star Son was taunted by Millwall supporters during Tottenham's 6-0 victory at White Hart Lane and responded to the jibes with a hat-trick.
Asked about the chants of "dvd" and "three for a fiver", which were perceived as a racial slur against Asians who sell black market films in London, Harris made it clear such taunts shouldn't be tolerated.
"Honestly I didn't hear anything but myself and the club, we won't condone that if there is," Harris said.
"I'm sure it will be investigated and left to the authorities. We want people dealt with harshly of course. It's a shame to be talking about this.
"We just want everyone to enjoy the game. It's wrong in society and wrong in football."
Millwall fans were also accused by Wolves boss Paul Ince of aiming the same racist chants at South Korea's Seol Ki-Hyeon in a match in 2005.
But Tottenham manager Mauricio Pochettino said Son hadn't complained about the chants after the match.
"No, Son didn't say anything," Pochettino said. "I didn't hear (the songs). It's difficult for me to understand the crowd."