All persons having claims against the state shall exhibit them, with supporting evidence to the commissioner of administration or his duly authorized representative to be audited, settled and allowed, within two years after the claim accrues. No claim or debt shall be allowed against the state unless exhibited to the commissioner of administration or his duly authorized representative, except when it is proved that the claimant or creditor has vouchers which he could not produce to the commissioner of administration or his duly authorized representative on account of sickness, unavoidable accident or absence from the state.
La. R.S. § 39:339