Brentford Football Club say they will seek to take action following a "racist tweet" which was aimed at striker Clayton Donaldson.
The Bees drew 1-1 with Scunthorpe
on Saturday with Donaldson missing a first-half penalty.
"Brentford FC has been made aware of a racial comment posted on Twitter about Clayton Donaldson,"
said a statement.
"We take all forms of discrimination very seriously and will seek to take action against the person concerned."
The League One club have now asked for help in identifying the culprit, asking supporters to e-mail them.