Not sure how I missed this book, Theremin: Ether Music and Espionage by Albert Glinsky.
As a Soviet scientist, Theremin surrendered his life and work to the service of State espionage. On assignment in Depression-era America, he became the toast of New York society while passing data on U.S. industrial technology to the Soviet apparat. Following his sudden disappearance from New York in 1938, Theremin was exiled to a Siberian labor camp and subsequently vanished into the top-secret Soviet intelligence machine, presumed dead for nearly thirty years. Using the same technology that lay behind the theremin, he designed bugging devices that eavesdropped on U.S. diplomatic offices and stood at the center of a pivotal cold war confrontation. Throughout his life, Theremin developed many other electronic wonders, including one of the earliest televisions and multimedia devices that anticipated performance art and virtual reality by decades.