British cargo ship Kavak visited the Black Sea according to a letter of the German naval attaché at Istanbul dated 17 February 1940

In his letter dated Istanbul, Turkey 17 February 1940 No. 758 g. reported the German naval attaché to the Oberkommando der Wehrmacht Abteilung Ausland the neutral ships passing Istanbul coming out of the Black Sea and loaded with contraband for or chartered by the enemy. An item reported on 12 February the British cargo ship Kavak loaded with tobacco, mohair, seeds, hazelnuts and oil cakes for London, England, went in the evening of the 10th to Izmir to load more cargo for London and Liverpool, England.

Source

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