Millwall fans who targeted Tottenham forward Son Heung-min with racist chants should be dealt with strongly, says Lions boss Neil Harris.
South Korea international Son was subjected to chants of "DVD" and "he's selling three for a fiver" during Sunday's FA Cup sixth round tie.
The chants seem to refer to a racist stereotype of Asians as traders selling bootleg copies of films door to door.
"It's a shame to be talking about this," added Harris.
Son scored a hat-trick as Spurs beat League One Millwall 6-0 to reach the FA Cup semi-finals.
The Football Association could investigate and Harris said he wanted those responsible to be dealt with "harshly".
"Honestly I didn't hear anything but myself and the club, we won't condone that if there is," he added.
"I'm sure it will be investigated and left to the authorities.
"We want people dealt with harshly of course. It's wrong in society and wrong in football."
Lord Ouseley, chairman of anti-racism group Kick It Out and a Millwall fan, said he was unaware of the offensive interpretation of the chants.
"If complaints are made they will have to be looked at to see if they have any validity to see if it stirs up racial hatred," Ouseley told The Associated Press news agency.