Section 6814. Records of shipment

For the purpose of enforcing provisions
  of this article, carriers engaged in  commerce,  and  persons  receiving
  drugs,  devices  or  cosmetics  in  commerce or holding such articles so
  received, shall, upon the request of an officer  duly  assigned  by  the
  secretary,  permit  such officer, at reasonable times, to have access to
  and to copy all records showing the movement in commerce  of  any  drug,
  device  or  cosmetic,  or  the  holding  thereof  during  or  after such
  movement, and the quantity, shipper, and consignee thereof: and it shall
  be unlawful for any such carrier or person to fail to permit such access
  to and copying of any such record so  requested  when  such  request  is
  accompanied  by  a statement in writing specifying the nature or kind of
  drug, device or cosmetic to which such request relates:  Provided,  that
  evidence  obtained  under  this  section shall not be used in a criminal
  prosecution of the person from whom obtained:   Provided  further,  that
  carriers shall not be subject to the other provisions of this article by
  reason of their receipt, carriage, holding or delivery of drugs, devices
  or cosmetics in the usual course of business as carriers.