JUDGMENT

PATHAK, CJI. :— The facts in these appeals he within a narrow compass. One Abdulhussein Gulamhussein Merchant died on 8 February, 1959. The accountable persons filed returns under the provisions of the Estate Duty Act, 1953 and an assessment was made by the Deputy Controller of Estate Duty on 26 February, 1960. The Estate Duty (Amendment) Act, 1958, repealed the original sections 56 to 65. Section 59, which substituted for the original S. 62, made provision for reassessment. It came into force with effect from I July 1960. On 21 February, 1962 a notice under the new S. 59 of the Act was issued to the accountable person concerned for reopening the assessment on the ground that some property had escaped the levy of estate duty. The accountable persons raised objections to the reopening of the assessment under S. 59. The Assistant Controller rejected the contentions of the accountable persons and reopened the assessment. Against the order of reassessment the accountable persons filed three different appeals before the Appellate Controller. The Appellate Controller allowed the appeals and set aside the reassessment orders holding that S. 59 under which action had been taken by the Assistant Controller was not retrospective in operation. On appeal by the Revenue, the Tribunal upheld the view of the Appellate Controller relying on the decision of the Bombay High Court in A. N. Mafatlal v. Dy. Controller of Estate Duty, (1968) 67 ITR 449. Thereafter three references were made to the High Court at the instance of the Revenue raising the identical question :

"Whether Section 59 of the Estate Duty Act, 1953 is retrospective in operation and if so, in the facts and circumstances of the case, the reopening of the assessment under S. 59 of the said Act was bad in law?"

Section 62 as originally enacted read as follows :-

"Rectification of mistakes relating to valuation for estate duty :- (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 has been the subject matter of an appeal under the 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 any property, the period will be six years :

Provided further that no order shall be made under this sub-section unless the person accountable has been given an opportunity of being heard.

(2) Nothing contained in sub-section (1) shall render any person accountable to whom a certificate that the estate duty has been paid is granted liable for any additional duty in excess of the assets of the decased which are still in his possession, unless the person accountable had fraudulently attempted to evade any part of the estate duty in the first instance."

2. The provisions of section 59 introduced by the Amendment Act of 1958 are as follows:

"59. Property escaping assessment :- If the Controller ..............

(a) has reason to believe that by reason of the omission or failure on the part of the person accountable to submit an account of the estate of the deceased under Section 53 or Section 56 or to disclose fully and truly all material facts necessary for assessment, any property chargeable to estate duty has escaped assessment by reason of under valuation of the property included in the account or of omission to include therein any property which ought to have bee