Avon and Somerset Police says it is investigating after Bristol City forward Famara Diedhiou was racially abused on social media.
The Senegal striker, 27, posted a screenshot of a message containing three banana emojis on Twitter after City's 1-0 loss at Swansea on Saturday.
Diedhiou missed a penalty in the game.
"We're aware of a racist social media message directed at a Bristol City FC player and a formal report has been made to us," said a police statement.
"Our football liaison officer has been in touch with the club to offer support and confirm an investigation will be carried out. They will be speaking to the affected player in due course to take more details and extend this support directly to him.
"We've contacted Twitter to ensure the post is removed and to get further details about the offender. Early indications suggest the message may have originated from an account holder outside of this country.
"Racist messages of any kind are abhorrent and we want to reassure the player and the club that a full and thorough investigation will now take place."
The Championship club posted on Twitter: "We stand with Famara Diedhiou and anybody who has to suffer racism in any shape or form. There is no excuse or justification for this disgusting behaviour."
Diedhiou is Bristol City's leading scorer this season with 13 goals in all competitions.