On 20 July 1944, Ziehlberg was ordered to arrest his "Ia" staff officer Major Joachim Kuhn for his involvement in the 20 July plot. Kuhn together with his friend Lieutenant Albrecht von Hagen had arranged for the explosive delivered by Helmuth Stieff to Claus von Stauffenberg. On 21 July he had accompanied General Henning von Tresckow to the front near Królowy Most, where Tresckow committed suicide. Confronted with the warrant, Kuhn denied any entanglement. Instead of arresting him, Heisterman told Kuhn to transfer his official duties and to proceed to Berlin in order to clear things up. Kuhn used that opportunity to flee towards the forces of the Soviet 2nd Belorussian Front. He was taken prisoner and interrogated by the SMERSH counter-intelligence agency.