Zenit St. Petersburg have confirmed they will investigate a racist incident involving the club's supporters and Anzhi Makhachkala defender Roberto Carlos.
During last weekend's 2-0 win for the home side, a Zenit fan was pictured offering the Anzhi captain a banana from the terraces, prior to kick off.
The Russian champions have said they will work alongside police to investigate the matter fully, and a note on their official website reads: "In regards to a published photo of a man making an unethical act towards Anzhi captain Roberto Carlos, Zenit officially state that the club, together with the police, will investigate this matter."
Carlos though was unconcerned by what happened, saying briefly: "I didn't get offended. In my 37 years I've seen it all so I didn't get upset after seeing a banana."
If found guilty, the Russian club could be fined, forced to play home games behind closed doors or have points deducted.