ORDER 1. These appeals are directed against the judgment and order of the High Court of Andhra Pradesh dismissing writ petitions filed by the appellant. The writ petition impugned notices issued by the Deputy Commissioner of Taxes, Visakhapatnam, under the provisions of Section 20 of the Andhra Pradesh General Sales Tax Act, 1957 (6 of 1957). The notices pertained to the years 1956-57, 1957-58, 1967-68, 1968-69 1969-70 and 1970-71. The notices stated that during these periods iron ore and manganese ore were taxable at the time of purchase by the last dealer in the State. The appellants had figured as the last purchasers of the goods in the State since the purchase of iron ore and manganese ore involved in the turnover were exported immediately thereafter. The benefit of Article 286(1)(b) of the Constitution extended to transactions which came within the meaning of the phrase "in the course of export". In view of the decision of the Supreme Court in Mohd. Serajuddin v. State of Orissa [ (1975) 2 SCC 47 : 1975 SCC (Tax) 269 : (1975) 36 STC 136], it was clear that transactions anterior to the actual export were not within the scope of the exemption. Therefore, the exemption that had been allowed by the Assistant Commissioner on the purchases of iron ore and manganese ore was erroneous and was proposed to be cancelled and the turnover in this behalf restored the assessment to tax. The show-cause notice called upon the appellants to tender objections to such course being adopted. 2. The High Court took the view that the judgment in Mohd. Serajuddin case [ (1975) 2 SCC 47 : 1975 SCC (Tax) 269 : (1975) 36 STC 136] had declared the law and that it was, therefore, open to the Deputy Commissioner of Commercial Taxes to invoke powers under Section 20 of the said Act. 3. Section 20(1), as it then read, empowered the Commissioner of Commercial Taxes to call for and examine the record of any order passed or proceeding recorded by any subordinate authority, officer or person under the provisions of the said Act for the purpose of satisfying itself as to the legality or propriety of such order or as to the regularity of such proceeding and to pass such order in reference thereto as it though fit. The power in this behalf were, by reason of Section 20(2), also exercisable by, inter alia, the Deputy Commissioner. 4. The case of Mohd. Serajuddin [ (1975) 2 SCC 47 : 1975 SCC (Tax) 269 : (1975) 36 STC 136], clearly, declared the law relevant to the transactions in question. It was open to the Deputy Commissioner of Commercial Taxes to suo motu call for and examine the record of orders and proceedings to which the case would apply and to satisfy himself as to the legality, propriety and regularity thereof and to pass such other orders in reference thereto as he thought fit. The issuance of the show-cause notices impugned by the appellant in the writ petitions was, in our view, perfectly legal. The High Court was right in so holding. 5. We make it clear that we have expressed no opinion upon the merits of the issue involved in the show-cause notices. The issue shall be decided by the appropriate authority independently of and without reference to any observations in the judgment under appeal. 6. The appeals are dismissed. There shall be no order as to costs.