Millwall have admitted to being "extremely disappointed" with Leicester City after the Premier League champions failed to raise their grievances immediately after Saturday's FA Cup clash.
The Foxes lodged a complaint to the Football Association regarding "numerous complaints" of abuse in the aftermath of their 1-0 loss at The Den.
It is understood that the complaint centres around alleged abuse directed towards players and supporters at full time, which led to the Metropolitan Police making three arrests, but Millwall have hit back at the way in which Leicester have dealt with the situation.
"We have been made aware of these allegations today and are extremely disappointed that Leicester City, as is the professional protocol in such instances, did not raise them on the day of the game itself," a club statement read.
"This morning we received an email from Leicester thanking Millwall Football Club for the hospitality extended to them so are surprised that these serious allegations, which should have been discussed on the day, have come to our attention in the manner they have."
Millwall's reward for reaching the last eight of the competition is a trip to take on Tottenham Hotspur in what will be the last cup tie staged at White Hart Lane.
