In addition to the salaries, expenses and fringe benefits of district attorneys and legal assistants authorized by Section 25-3-35(5) and (6) and criminal investigators authorized by Section 25-31-10(5), the salary of a district attorney may be supplemented in an amount not to exceed Eight Thousand Three Hundred Dollars ($8,300.00) per year; the salary of a legal assistant may be supplemented in an amount not to exceed Six Thousand Dollars ($6,000.00) per year; and the salary of a criminal investigator may be supplemented in an amount not to exceed Five Thousand Dollars ($5,000.00) per year, payable monthly. The supplemental salary, expenses and fringe benefits authorized herein may be paid from office-generated funds, funds from a county, a combination of counties, a municipality, a combination of municipalities, a county and a municipality, a combination of counties and municipalities, federal funds, grants from private foundations, or by means of an Interlocal Cooperative Agreement authorized by Section 17-13-1. The district attorney shall report to the board of supervisors of each county comprising the circuit court district the amount and source of the supplemental salary, expenses and fringe benefits, and the board in each county shall spread the same on its minutes. The district attorney shall also report such information to the Department of Finance and Administration who shall make such information available to the Legislative Budget Office. The supplemental salary, expenses and fringe benefits may either be paid from district attorney accounts, transferred by the district attorney to the Department of Finance and Administration or to one or more of the separate counties comprising the circuit court district, and such funds shall be disbursed to the employees in the same manner as state-funded criminal investigators and full-time legal assistants.