Rudolf Hamburger had been arrested less than two years before the end of the war. After war ended his brother Viktor, living in Missouri, and his ex-wife, who till 1949 lived in an Oxfordshire village, began to receive occasional reports about him via fellow internees who had emerged from the Soviet labour camps. Rudolf Hamburger was not permitted to send or receive letters. In July 1947 Viktor received a letter from a Polish woman who reported that Rudolf was alive and "working as an engineer". His ex-wife, Ursula, wrote to Viktor in August 1947 that she had also received a letter from Poland: "He is a prisoner for five years, but works in his profession. (...) I do not know when the five years will be over. She has been in the same camp with him from July 1945 to December 1946". At this time Hamburger himself was being held at Karaganda in Kazakhstan, and the letters from Poland evidently predated his second sentencing in May 1949.