German merchant ship at Hamburg loaded with unkown cargo for unknown destination in July 1939

The American Naval attaché at Berlin reported on 17 July 1939 No. R-439 that during his visit to Hamburg, Germany over the past-weekend he was informed that a Hamburg-American Line cargo ship had its regular sailing cancelled and was being loaded with an unknown cargo.

Source

National Archives USA. Record Group 38: Records of the Office of the Chief of Naval Operations. Series: Secret Naval Attaches Reports. selected naval attaché reports relating to the world crisis, 1937-1943. Probability of an Outbreak of War (pt.). Berlin. Roll M975-003.