Kamara claimed he was racially abused by Ondrej Kudela during Rangers' Europa League defeat to Slavia on Thursday.
Kudela, who covered his mouth with his hand, leaned into Kamara and said something that sparked fury from the Rangers man and a nearby team-mate.
The Czech club have strenuously denied the allegations and issued a statement on Friday defending Kudela, who they allege was subjected to an attack by Kamara after the match.
Slavia also revealed they had filed a criminal complaint against Kamara for the alleged attack.
UEFA has launched an investigation into the respective incidents, including the claimed post-match altercation, which Slavia claim was "prepared and thought out, including deliberately covering the cameras at the scene of the incident".