Right if could be enforced through writ proceedings.

These petitions for certiorari by different assessees raise a common point and have, hence, been heard together. It will

suffice to notice the facts in the first of these petitions, to determine the main questions. The Asea Electric (India) Private

Limited, paid a sum of Rs. 42,915-58 as tax at six per cent on the turnover of Rs. 6,60,239-66, being the value of

machinery imported from Sweden and sold to Bharat Heavy Electricals Limited, under a permit therefor issued to the

latter by the Assistant Controller of Imports, under the Import Trade Control Regulations The permit was dated 12th

November, 1964. According to the terms of the contract between the parties, the seller was paid 90 per cent of the

invoice value and the sales tax in full when presenting the invoices to the purchaser. That was on 4th February, 1966. A

second invoice also was presented on 24th March, 1966 The assess ment was on the combined values under both the

invoices. The seller in its return for the year 1965-66, showed the turnover as chargeable to tax and did not claim any

exemption, on the ground that it related to import sales of the goods On 18th January, 1966 the Supreme Court

decided Khosla &Co. (P.) Ltd. v Deputy Commissioner of Commercial Taxes1. If the facts, as stated in the affidavit in

support of the writ petitions, are correct, there can be no doubt that, in view of this decision the sales would not attract

tax.

The purchaser is a wholly Government-owned company, with its registered office at Delhi, and having some of its units

in the State of Madras After Khosla & Co. (P.) Ltd. v. Deputy Commissioner of Commercial Taxes1, came to its

notice it instructed its units to claim refund of the relative taxes, not exigible under the law, from the respective sellers.

The sellers corresponded with the Department at different stages, but m vain. Eventually, the sellers and the purchaser

have joined in filing the petition for quashing that part of the assessment of the sellers which related to the said

transactions. The facts in the other petitions are similar, excent for the fact that they are by different assessees and the

figures of the turnover and actual tax levied, are also different.

As we said, if the transactions bear the character which the petitioners claim they did, Khosla &Co. (P.) Ltd., v. Deputy

Commissioner of Commercial Taxes1, would clearly apply to them, with the result the import sales will be exempt from

tax It is well-established that if an assessee has paid tax, though voluntarily, but by mistake of law, he is entitled to ask

for refund of such tax means of a petition under Article 226 of the Constitution. The leading authority, followed

subsequently in several cases, is Sales Tax Officer v. Kanhaiya Lal Makund Lal Saraf2, State of Kerala v Aluminium

Industries Ltd.3, establishes two propositions: (1) where a tax is levied by mistake of law, it is ordinarily the duty of the

State, subject to any provision in the law relating to sales tax, to refund the tax: no question of estoppel will arise when

the mistake of law is common to both the parties ; and (2) if refund is not made, remedy through Court is open subject

to the same restrictions and also to the period of limitation, namely, three years from the date when the mistake becomes

known to the person who has made the payment by mistake. The right to apply for refund in the instant cases arose on

18th January, 1966, when the Supreme Court decided Khosla &Co. (P.) Ltd.v. Deputy Commissioner of Ccmmercial

Taxes1, and the writ petitions have been filed well within the period of three years. A prayer for refund con-not be

refused by Courts merely on the ground that although the character of the transactions prima facie appears, it had not

been fully investigated. In such a case, either a report will have to be called for from the authority concerned, containing

its finding on the question, as was done in State of Kerala v. Aluminium Industries Ltd.2 or the question remi