The taxes paid on tobacco products, and cigarette papers and tubes may be refunded (without interest) to an export warehouse proprietor on proof satisfactory to the appropriate TTB officer that the claimant proprietor paid the tax on such articles which were after taxpayment lost (otherwise than by theft) or destroyed, by fire, casualty, or act of God, while in the possession or ownership of such export warehouse proprietor, or withdrawn by him from the market. Any claim for refund under this section shall be prepared on Form 5620.8, in duplicate, and shall include a statement that the tax imposed by 26 U.S.C. 7652 or chapter 52, was paid in respect to the articles covered by the claim, and that the articles were lost, destroyed, or withdrawn from the market within 6 months preceding the date the claim is filed. The claim must be filed on TTB Form 5620.8 and supported by such evidence as is necessary to establish to the satisfaction of the appropriate TTB officer that the claim is valid. The duplicate of the claim shall be retained by the export warehouse proprietor for 3 years following the close of the calendar year in which the claim is filed. Where an export warehouse proprietor has paid the tax on tobacco products, or cigarette papers or tubes, he may file claim for refund of an overpayment of tax under subpart A of part 46 of this chapter if, at the time the tax was paid, these articles had been exported, destroyed, or otherwise disposed of in such a manner that tax was not due and payable.