In addition to the grounds and reasons now set forth and provided by law for which the district court may grant authority to administrators or executors of the estates of deceased persons to mortgage, by contract, renewal or new mortgage, the real estate of such estates, the district court may, upon verified petition supported by sufficient evidence showing that the best interest of the owners of the real estate belonging to any such estate requires it, by an order, grant authority to such administrators or executors to mortgage the real estate, or any part thereof, except the homestead, belonging to an estate of a deceased person for the purpose of borrowing or securing money and funds with which to pay off and discharge outstanding and unpaid debts against the estate of such deceased persons, legally ordered and unpaid family allowance and expenses and charges of administration, whether said property has or has not before that time been mortgaged by the decedent or by the administrator or executor of his estate.