Ursula Kuczynski

Ursula Kuczynski (15 May 1907 – 7 July 2000), also known as Ruth Werner, Ursula Beurton and Ursula Hamburger, was a German Communist activist who spied for the Soviet Union during the 1930s and 1940s, most famously as the handler of nuclear scientist Klaus Fuchs. She moved to East Germany in 1950 when Fuchs was unmasked, and published a series of books related to her espionage activities, including her bestselling autobiography, ''Sonjas Rapport''.

Sources concerned with her espionage work in the 1930s/40s sometimes use the cover name originally suggested to her in Shanghai by her fellow intelligence operative and lover Richard Sorge: "Sonja", "Sonja Schultz" or, after she moved to Britain, "Sonya". Provided by Wikipedia