Millwall have promised to reopen an investigation into allegations of racial abuse aimed at a Leeds player during a match in London earlier this season.
The Lions won the match on November 18 1-0 but an allegation of online abuse was made after the contest.
TV footage shown by Sky Sports News as part of an investigation into racism in the game showed Leeds' Senegal international forward El-Hadji Diouf being racially abused.
"Like all Millwall fans and football fans generally, we're appalled by the footage we've seen.
"Clearly that behaviour is unacceptable in any football ground in the country and at Millwall we will ban the individuals for life and we hope that Sky will pass the footage to the police so that further action can be taken.
"Sadly racism exists in our society and certain individuals want to bring it into football grounds. It's down to us in football do to more.
– Millwall chief executive Andy Ambler
"After speaking to the player who had the alleged abuse at him during the day,
he said that he heard no abuse on the day so that was basically at that point
the end of the investigation - although we're going to open it again now."