Everton's Arouna Kone says he was racially abused by a spectator after scoring the opening goal in his side's FA Cup win at Carlisle.
The striker reported the incident to referee Lee Mason early on in the 3-0 fourth round victory, with his team-mates Steven Pienaar and Aaron Lennon also appearing to react in the direction of the abuse.
An announcement was then made on the public address system that abuse would not be tolerated.
Cumbria Police issued the same message on Twitter, asking anyone with information to report it.
Racism will not be tolerated in Cumbria. Anyone with information on any racist chanting at the @officialcufc game please report it to 101
— Cumbria Police (@Cumbriapolice) January 31, 2016
"We are investigating allegations of racist behaviour directed towards Everton players following the first goal," confirmed Carlisle Constabulary Superintendent Justin Bibby.
Everton manager Roberto Martinez also spoke out about the incident after the game.
"It was just a reaction, something that we don't want to see. It was just a reaction to the celebration of the goal and that was it. It would be wrong to highlight such a moment in an enjoyable footballing festivity," he said.
