Millwall manager Neil Harris condemned racist chanting as “wrong in society and wrong in football”, after Tottenham striker Son Heung-min was targeted by Millwall fans at White Hart Lane, insisting that he wants perpetrators to be dealt with “harshly” by the authorities.

Whenever South Korean international Son touched the ball in the first half there were loud chants of “DVDs, DVDs” from the 3,600-strong away end at White Hart Lane. The away fans also sang a song about Son selling “three [DVDs] for a fiver”.

Both Harris and Spurs manager Mauricio Pochettino said afterwards that they did not hear any of the racist chanting, but Harris was clear that he would like to see heavy punishments for those guilty of it.

“Honestly I did not hear anything,” Harris said in his post-match press conference. “Me personally, but also the club, we will not 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.”

The FA have been closely following developments and will investigate this week. They will speak to referee Martin Atkinson, to both clubs and to the Metropolitan Police before deciding whether to bring charges. Harris said that when the FA look into the matter, he would support strict measures against proven offenders.

“I am sure it will be left to the authorities,” Harris said. “We just want people to enjoy the game. That’s the main thing. For us as a club we want to focus on achievement of getting here. We want people to be dealt with harshly, of course.”

This was a brilliant FA Cup run from Millwall, reaching the quarter-finals, beating three Premier League teams along the way. Harris said that it was a “shame” to be talking about the behaviour of some Millwall fans rather than their football achievements after this game.

Tottenham 6 Millwall 0 player ratings Show all 22 1 /22 Tottenham 6 Millwall 0 player ratings Tottenham 6 Millwall 0 player ratings Michel Vorm – 5 out of 10 It was a quiet day at the office for the keeper due to very few attempts from the Millwall forwards. Getty Images Tottenham 6 Millwall 0 player ratings Eric Dier – 6 out of 10 Had a relatively straight forward day at the back, with few very Millwall moves causing him an issue. Getty Images Tottenham 6 Millwall 0 player ratings Toby Alderweireld – 6 out of 10 A disciplined display from the central defender. Did his job and held his shape at the back. Getty Images Tottenham 6 Millwall 0 player ratings Jan Vertonghen – 6 out of 10 Defended bravely and began moves from the back. Read the game well. Getty Images Tottenham 6 Millwall 0 player ratings Kieran Trippier – 7 out of 10 His assist for Son’s goal was sublime, as were the rest of his deliveries into the danger zones throughout. Getty Images Tottenham 6 Millwall 0 player ratings Victor Wanyama – 6 out of 10 Battled throughout and was a key element to Tottenham’s moves going forward. Getty Images Tottenham 6 Millwall 0 player ratings Harry Winks – 7 out of 10 Oozes confidence for a young lad and it was good to see taking shots on goal. Tottenham Hotspur FC via Getty I Tottenham 6 Millwall 0 player ratings Ben Davies – 7 out of 10 Was charging up and down the wings, which provided Spurs with the width that they required. Tottenham Hotspur FC via Getty I Tottenham 6 Millwall 0 player ratings Son Heung-min – 9 out of 10 The hat-trick hero was on fire today. His movement, work rate and finishing were all spot on. Tottenham Hotspur FC via Getty I Tottenham 6 Millwall 0 player ratings Dele Alli – 7 out of 10 His goal marked his 16th of the season. His positioning was spot on today and he was always making space going forward. Tottenham Hotspur FC via Getty I Tottenham 6 Millwall 0 player ratings Harry Kane – N/A Went off in the early stages of the game after losing his balance and appearing to injure his ankle. AFP/Getty Tottenham 6 Millwall 0 player ratings Tom King – 3 out of 10 Made a handful of important saves, but it’s never a good day when you concede six. Tottenham Hotspur FC via Getty I Tottenham 6 Millwall 0 player ratings Shaun Cummings – 4 out of 10 Defended very narrowly, which allowed Spurs to cause damage in the wide areas. AFP/Getty Images Tottenham 6 Millwall 0 player ratings Byron Webster – 5 out of 10 Struggled to cope with Tottenham's pace going forward. CameraSport via Getty Images Tottenham 6 Millwall 0 player ratings Jake Cooper – 5 out of 10 Heung min-son made his life very difficult. AFP/Getty Images Tottenham 6 Millwall 0 player ratings Tony Craig – 5 out of 10 Defended bravely, but simply failed to contain the Spurs strikers. Getty Images Tottenham 6 Millwall 0 player ratings Jed Wallace – 6 out of 10 He tracked back and worked hard defensively, but failed to show any ability going forward. Getty Images Tottenham 6 Millwall 0 player ratings Ben Thompson – 5 out of 10 Lost the battle in the midfield and this allowed the opponents to dominate the play. Getty Images Tottenham 6 Millwall 0 player ratings Shaun Williams – 6 out of 10 His deliveries up the field were impressive, but they lacked the final product. Tottenham Hotspur FC via Getty I Tottenham 6 Millwall 0 player ratings Aiden O’Brien – 5 out of 10 Was forced to drop deep due to the quality of the Spurs defence. He was marked out of the game. AFP/Getty Images Tottenham 6 Millwall 0 player ratings Lee Gregory – 6 out of 10 His work rate was faultless, but he did not have enough time on the ball to actually make an impact. Getty Images Tottenham 6 Millwall 0 player ratings Steve Morison – 6 out of 10 Looked the most dangerous prospect for Millwall going forward. Getty Images

“Yes of course [it is a shame] for both of us,” Harris said. “Mauricio wants to be talking about his team's quality. The focus comes away from what we've achieved in the competition. It's wrong in society, and it's wrong in football.”