If, on examination of the TTB Form 5100.11 (and attached gauge reports, if any) received from the officer required to certify the same under the provisions of subpart N of this part, the appropriate TTB officer is of the opinion that the distilled spirits reported lost had been unlawfully diverted, or had been lost by theft, he will advise the exporter by letter:
In any case in which distilled spirits are lost during transportation, as described in § 28.301 , whether by theft or otherwise, the appropriate TTB officer may require the exporter to file a claim for relief in accordance with § 28.303 . When circumstances may warrant, extensions of additional time for submission of the proof and claim may be granted by the appropriate TTB officer. Where such proof and claim are not filed within the 30-day period, or such extensions as the appropriate TTB officer may grant, the tax on the distilled spirits diverted or lost will be assessed, or liability asserted against the bond covering the shipment, as the case may be.
27 C.F.R. § 28.302
Sec. 201, Pub. L. 85-859, 72 Stat. 1323, as amended ( 26 U.S.C. 5008 )