(1)If, after the determination of the estate duty payable in respect of any estate, it appears to the Controller, that by reason of any mistake apparent from the record or of any mistake in the valuation of any property in any case other than a case in which the valuation of any property in any case other than a case in which the valuation has been the subject matter of an appeal under this act or of the omission of any property, the estate duty paid thereon is either in excess of or less than the actual duty payable, he may, either on his own motion or on the application of the person accountable and after obtaining the previous approval of the Board, at any time within three years from the date on which the estate duty was first determined.(a)refund the excess duty paid, or as the case may be,(b)determine the additional duty payable on the property:Provided that where the person accountable had fraudulently under estimated the value of any property or omitted and property the period shall be six year:Provided further that no order shall be made under this sub-section unless the person accountable has been given an opportunity of being heard.
