A. Each district attorney of this state is hereby authorized to employ one special investigator in addition to any others previously authorized by law, to be known by the title of "District Attorneys' Investigator".
B. The special investigator shall receive an annual salary payable by the state, of six thousand dollars. In addition, the governing authorities of the parish or parishes comprising any judicial district may provide and pay an additional compensation to these investigators.
C. No district attorney shall employ a special investigator as authorized by this section until and unless the funds to pay the state's portion of the salaries of such special investigators are appropriated or otherwise made available therefor.