Antoni Kocjan proved paramount in his involvement with the Polish Home Army. On June 13, 1940, a Wasserfall antiaircraft rocket, a secret missile also built by the Germans at Peenemünde East, equipped with a revolutionary radio system that gave it remote control capabilities landed in Malmö, a city located in the south of Sweden - a neutral country during World War II. The Swedish authorities were quickly notified and in response, the Swedish Air Force guarded the impact site and the Wasserfall rocket. On July 10, about a month later, Stewart Menzies, Chief of MI-6 in London at the time was informed of the rocket in Sweden and upon knowledge of its German authenticity, immediately began negotiations with Swedish administrators to retrieve the rocket. An agreement was finally made that in return for the rocket, the British were to supply the Swedish army with two squadrons of tanks.