The Attorney General or the officer authorized by the law of the State of Mississippi to collect any tax owing to the State of Mississippi or its political subdivisions, is hereby authorized to employ attorneys residing in a sister state, district or territory, where suits are instituted to recover taxes due the State of Mississippi, pursuant to this chapter, to aid and assist in the prosecution of any such suit, when it appears to be in the best interest of the State of Mississippi. It is further provided that such attorney fees may, within the discretion of the designated officers, be set on a fixed or contingent fee basis. The fixed fee shall be paid out of the fund appropriated for the operation of the office of such officer bringing suit, and the contingent fee shall be deducted from and paid out of the proceeds of the particular claim, subject, however, to the approval of the Governor as to the employment and amount of such fee in either instance.