Rotherham United join police in Twitter racism probe after Cardiff City match
The vile tweets were aimed at visiting centre-half Cedric Kipre who scored a late winner for the Bluebirds at AESSEAL New York Stadium in the Championship survival showdown.
They were quickly deleted but evidence of them exists as they were screenshotted and shared on the social-media site.
The Millers moved swifty to condemn the tweets in a statement on their website less than two hours after the final whistle.
They said: "A number of social-media posts were brought to the club’s attention in the immediate aftermath of the game. We are now seeking to identify the individual in question and will work alongside South Yorkshire Police to bring the perpetrator to justice.
"The club totally dissociates itself from the actions of this individual and the abhorrent behaviour that they have displayed."
Rotherham said they would be making no further comment.
The 2-1 defeat leaves the Millers needing three point from their last two matches to be sure of staying in the second tier.
They are now preparing for Monday's home match with Middlesbrough, who have already secured a play-off spot. Only a few tickets remain and a sell-out bank-holiday crowd is expected for the 1pm kick-off.