(1) Where an amount required to be refunded by the prescribed authority to any person is not refunded to him or the application for refund is not rejected, as the case may be, within ninety days of the amount having become refundable, the prescribed authority shall pay such person simple interest at the rate of six per cent. per annum or part thereof on the said amount from the date immediately following the expiry of the period of ninety days to the date of the refund:
Provided that where the amount becomes refundable by virtue of an order of the Tribunal or the High Court or the Supreme Court, the interest under the provisions of this section shall be payable from the date immediately following the expiry of the period of ninety days from the date of receipt of the order of the Tribunal, the High Court or the Supreme Court, by the officer whose order forms the subject matter of the proceedings before the Tribunal, the High Court or the Supreme Court, to the date of refund.
(2) If the delay in granting the refund within the period of ninety days aforesaid is attributable to the said person, whether wholly or in part, the period of the delay attributable to him shall be excluded from the period for which interest is payable.
(3) Where any question arises as to the period to be excluded for the purposes of calculation of interest under the provisions of this section, such question shall be determined by the Commissioner, whose decision shall be final.