(a) The county attorney or an assistant county attorney of each county of the state which does not have a county auditor and which has a population of less than 70,000 shall meet with the board of county commissioners of such county at each session when bills and accounts are presented for allowance, examine such bills and accounts, ascertain, as far as possible, the correctness of such accounts and give an opinion to the board of county commissioners as to the liability of the county for them. No bill shall be allowed by the board of county commissioners until the county attorney has passed upon it.

(b) If there is a county counselor of a county which is subject to this section, the county counselor shall perform the duties imposed on the county attorney by this section.