LAW on the Implementation of the Statute of the International Criminal Court and the Prosecution of Crimes against International Law of War and Humanitarian Law
III. NOTIFICATION T O THE PROSECUTOR AND ACTION T O BE TAKEN UPON THE PROSECUTOR'S NOTIFICATION
Article 19
(1) Upon receipt of the notification referred to in Article 18, paragraph 1 of this Law, the Public Attorney General and other competent state authorities, unless a legal procedure to this effect is already under way in the Republic of Croatia, shall take urgent action to determine if there is a reasonable basis to proceed under the notification, conduct required investigation and report without delay to the Government of the Republic of Croatia on the action thus taken.
(2) Within one month following the receipt of the notification the Government of the Republic of Croatia shall notify the Prosecutor if the requested criminal prosecution is under way in the Republic of Croatia.
(3) If the criminal prosecution has been commenced in the Republic of Croatia, the Government of the Republic of Croatia may request the International Criminal Court to have the case concerned referred to it.
(4) If the Pre-Trial Chamber of the International Criminal Court, in spite of the readiness to conduct criminal proceedings in the Republic of Croatia, authorises the Prosecutor to commence investigation, the Republic of Croatia may lodge a complaint in accordance with the Statute and the Rules of Procedure and Evidence.
(5) The Public Attorney General shall regularly report to the Government of the Republic of Croatia on actions taken and procedures conducted and the Government shall pass on such information to the Prosecutor, if required or requested.
Complementarity
ICC investigation - national procedures
Deferral of case by ICC to State
Initiation of ICC investigation
EDIT.