19 C.F.R. § 162.4 Search for letters.
Title 19 - Customs Duties
A Customs officer may search vessels for letters which may be on board or may have been conveyed contrary to law on board any vessel or on any post route, and shall seize such letters and deliver them to the nearest post office or detain them subject to the orders of the postal authorities. [T.D. 72–211, 37 FR 16488, Aug. 15, 1972]
Title 19: Customs Duties
PART 162—INSPECTION, SEARCH, AND SEIZURE
Subpart A—Inspection, Examination, and Search
§ 162.4 Search for letters.