Millwall say they have no evidence of racial abuse being directed at Preston striker Nathan Ellington on Saturday.
Ellington alleged on his Twitter page that he had been the subject of racist abuse and he called the Millwall fans a "disgrace to the human race".
"Never seen a more racist and abusive crowd as I saw today," he added.
But Millwall said no complaints had been made on the day by Preston or the match officials and the TV broadcaster had reported no evidence of racism.
Millwall beat Preston 4-0 to maintain their play-off push while North End moved closer to relegation.
Ellington added: "Major abuse while warming up, non stop, kids in the crowd as well but they don't care. Monkey noises, and calling me a thief, all players abused."
He continued: "I didn't bite or report it, it's just sad really that there are still people with so much anger at a football match.
"We were not good enough today, better team won, granted, not a sore loser at all. Just a portion of fans were abusive, most were fine.
"Most fans were fine, I played at most grounds in country but never had constant stick with genuine hate in faces."
But in a statement on their website, Millwall defended themselves against Ellington's accusations.
"Millwall are aware of accusations of racism made by Preston North End player Nathan Ellington on his Twitter site on Saturday night," said the statement.
"As a club we take the issue of racism extremely seriously and we are disappointed that if any individuals were guilty of engaging in racist behaviour on Saturday, it was not brought to our attention at the time so that we could identify the perpetrators.
"However, we received no complaints on the day from anyone connected with Preston North End or the match officials, and no evidence of racism was reported by the TV broadcaster who covered the match.
"We have resources at our disposal which have enabled us to assist police in successfully prosecuting individuals for racist behaviour in the past, and we have an acknowledged track record in terms of the progress we have made in this area.
"We have been at the forefront of the fight against racism, working closely with organisations including Kick It Out and Show Racism the Red Card, and will continue to do so."