Part Five. International Cooperation in the Sphere of Criminal Court Proceedings
Section XVIII. Procedure for the Interaction of Courts, Prosecutors, Investigators and the Inquest Bodies with the Corresponding Competent Bodies and Officials of Foreign States and with International Organizations
Chapter 53. Principal Provisions on the Procedure for the Interaction of the Courts, Prosecutors, Investigators and the Inquest Bodies with the Corresponding Competent Bodies and Officials of Foreign States and with International Organizations
4. If the inquiry cannot be executed, the received documents shall be returned with an indication of the reasons which have prevented it from being executed, through the body that has received it or along diplomatic channels, to that competent body of the foreign state, from which the inquiry was directed. The inquiry shall be returned without execution, if it contradicts the legislation of the Russian Federation, or if its execution may inflict damage upon its sovereignty or security .
Refusal of ICC request
Obligation to inform the Court of reasons for denial of assistance
EDIT.