Accurate accounts shall be kept under the direction of the board of all money received and disbursed by it, and a full statement thereof together with a complete statement in detail, of all work done, right-of-way acquired, and road constructed by said board shall be made to the board of supervisors of the county at its annual meeting each year. Such statement shall be published in the report of the proceedings of the board of supervisors. The accounts of said board of county road commissioners shall be reported to and audited by the board of supervisors at each meeting thereof or by any committee they may appoint for such purpose: Provided, That in counties having a board of auditors the accounts shall be audited by the board of auditors of that county, but the said board of auditors shall have no jurisdiction over the expenditure of any portion of the county road fund. Proof of filing of such statement with the board of supervisors, sworn to by the chairman of the board of county road commissioners, with copy of such statement annexed, together with sworn statement of the county clerk that such statement was published as a part of the proceedings of the board of supervisors shall be filed with the state highway commissioner within 30 days following such annual meeting.