When land which has been sold for taxes and purchased by the state has been sold by the state at private sale, and the purchase money has been paid into the state and county treasuries, and it shall be made to appear to the satisfaction of the Comptroller that such sale was invalid by reason of the fact that the taxes for which the land was sold were not due, the purchaser of said land from the state, his heirs, or assigns shall upon the surrender of the deed from the state and the cancellation of the same be entitled to have the purchase money paid for the said lands refunded, if application shall be made therefor, as hereinafter provided, within two years from the date of the deed made by the state.