§ 705. Prosecution fund. The board of supervisors shall have power to appropriate and set aside a fund for the payment in advance of audit of expenditures incurred by the district attorney, or attorney general acting under section sixty-two of the executive law, necessarily incurred in the prosecution of criminal actions and proceedings arising in the county. The board of supervisors may provide for such district attorney or attorney general to issue orders upon the county treasurer for such payment, the countersignature of the chairman of a designated committee of such board, accounting of such expenditures with verified or certified vouchers attached thereto and such other conditions and rules as may be deemed necessary. The claimant, district attorney and the attorney general in actions or proceedings prosecuted by him shall be jointly and severally liable for any item of expenditure for other than a lawful county purpose disallowed upon a final audit, to be recovered in an action brought against them by the board of supervisors in the name of the county.