The incident came to light shortly after Dagestan-based Anzhi's match in the Lokomotiv stadium, when a supporter called radio station Sport to report what had happened.
"Young people were running around the family sector of the stand, wearing tank tops...and a banana comes flying out of this crowd and hits Samba hard," said the supporter, who identified himself simply as Viktor, Sovetsky Sport reported. "Samba kept his cool — imagine, this two-meter-tall black guy does not want a banana and throws it back into the crowd at full strength."
The episode, which seemed to have racist overtones, follows a similar one from June 2011, when Samara-based team Krylya Sovetov was fined after one of their supporters threw a banana at Brazil legend and fellow Anzhi player Roberto Carlos. The team was penalized 100,000 rubles for a "racist prank" and 200,000 rubles for failing to keep order.
Samba initially refused to comment on Sunday's incident, but later Anzhi spokesman Alexander Udaltsov said the Congolese player hoped it could help teach children proper behavior.
"Let this incident serve as a bad example for the children who were present in the stadium," Udaltsov quoted Samba as saying.
Udaltsov also said Samba had the full support of the club for his reaction.
"In our opinion his response to whoever did it was correct," he said.
But Lokomotiv club president Olga Smorodskaya denied that the incident had taken place.
"What you are reporting does not reflect reality. This did not and could not have happened," she said. "I observed our supporters' behavior in the stadium and they showed exemplary support for their team."
Samba, 27, is a recent signing, having joined Anzhi from English team Blackburn Rovers for an undisclosed fee, estimated to be about $20 million.