Following Polish–Soviet War, the Second Department formed its outposts in main cities of the Soviet Union: Moscow, Leningrad, Kharkov, Kiev and Tiflis.
In the early 1920s, Polish services managed to convince an ethnic Pole, Bolesław Kontrym, who commanded Red Army's 28th Rifle Brigade, to change sides.
In 1924 – 27, Bydgoszcz office of the department, commanded by Major Marian Steifer, successfully carried out Operation Cart (Operacja Wozek), during which German correspondence between Berlin and East Prussia was controlled.
This office gathered all kinds of information regarding Nazi Germany, presenting daily and weekly reports to the Polish General Staff and the government.
Its sub-departments consisted of: The territorial structure of the Second Department of the Polish General Staff was divided into Samodzielne Referaty Informacyjne (SRI; English: Independent Information Offices), outposts, posts, branches.
As the Germans had failed to capture the documents of Czechoslovak military intelligence (in March 1939 they were transported by air to Britain), Admiral Wilhelm Canaris decided to form small groups of agents, which were attached to the frontline Wehrmacht units.
In Bydgoszcz, captured by the Germans on September 5, the agents immediately occupied offices of the local branch of the department, headed by Jan Zychon.
Warsaw capitulated on September 28, and a group of Abwehr agents immediately entered the office of the department, located on Pilsudski Square.
After opening over one hundred armoured wardrobes, they only came across a bunch of worthless German documents, such as train schedules, telephone directories, press articles and forms.
As Walter Schellenberg later recalled, after the return from Warsaw, where he had taken part in the victory parade (5 October 1939), he analyzed the captured documents for two days.
In his opinion, the quantity and quality of the archives was astounding, especially the information about German war industry, gathered by Polish agents.