British steamship Herport visited Turkey according to a letter of the German naval attaché at Istanbul dated 16 December 1939

In his letter dated Istanbul,  16 December 1939 No. 547g reported the German naval attaché to the Oberkommando der Wehrmacht Abteilung Ausland the ships passing Istanbul coming out of the Black Sea and loaded with contraband for the enemy. An item reported the departure of the British steamship Herport on 5 December from Izmir,  with the intention according her master to be loaded on the return voyage with stores for. Her cargo would be such important that she would be esorted and her master was worried. Time of departure and which harbour to be left was unknown. A second item claimed her passing on 10 December loaded with hasel nuts, wool and so on went towards Izmir for more cargo. The cargo was for Marseille, France and finally to England.

Source

Bundesarchiv. German Marineattaché for , Greece, Romania and Bulgaria 1939-1941. RM 12-II/459.