Hanecki first met Lenin in Brussels in 1903, and was in contact with him in Finland in 1907, and assisted him in moving his household to Cracow in 1912. He also persuaded Lenin to intervene in Polish affairs, siding with the Rozlamovists against Leo Jogiches and Rosa Luxemburg, and became one of Lenin's most trusted agents. He acted as chairman of the three man committee - whose other members were Lenin and Grigori Zinoviev - who looked into whether Roman Malinovsky, the former head of the Bolshevik parliamentary delegation, was a police spy, and wrongly exonerated him. Lenin and Hanecki were living in Poronin, a village close to the border, when war broke out between Austria and Russia in August 1914, and Lenin was threatened with arrest, as a Russian. Hanecki rescued him by arranging transport to the nearest town, Nowy Targ where - according to Lenin's widow - he warned the local chief of police that Lenin was an important figure in the world socialist movement and "a man for whose life he, the commander, would have to answer."
