Ignace Reiss

Ignace Reiss (1899 – 4 September 1937) – also known as "Ignace Poretsky," "Ignatz Reiss," "Ludwig," "Ludwik", "Hans Eberhardt," "Steff Brandt," Nathan Poreckij, and "Walter Scott (an officer of the U.S. military intelligence)" – was one of the "Great Illegals" or Soviet spies who worked in third party countries where they were not nationals in the late 1920s and 1930s. He was known as a ''nevozvrashchenec'' ("unreturnable").

An NKVD team assassinated him on 4 September 1937 near Lausanne, Switzerland, a few weeks after he declared his defection in a letter addressed to Joseph Stalin. He was a lifelong friend of Walter Krivitsky; his assassination influenced the timing and method of Whittaker Chambers' defection a few months later. Provided by Wikipedia