For many years, we have known that there were three spies at Los Alamos who passed atomic bomb secrets to the Soviets as the bomb was being developed during World War II. They were Klaus Fuchs, David Greenglass (the brother of Ethel Rosenburg), and Theodore Hall.
Now there is a fourth: Oscar Seborer.
His identity was uncovered through years of painstaking research by two academics, Harvey Klehr and John Earl Haynes. Their article is titled “On the Trail of a Fourth Soviet Spy at Los Alamos” is in the current issue of Studies in Intelligence, the CIA’s in-house journal.
Their work was covered in a recent article in the New York Times.
From an examination of archival materials from the K.G.B., the Soviet Union’s main intelligence agency, Mr. Klehr and Mr. Haynes learned about a shadowy group of moles in the United States known as the “Relative’s Group.” Three of the faction’s members — code-named Relative, Godfather and Godsend — were brothers. According to the study, the archival documents said that Godsend was at Los Alamos and that he was providing secret information on “Enormous,” the K.G.B.’s code name for the American project. Source: Fourth Spy Unearthed in U.S. Atomic Bomb Project – The New York Times
Klehr is an emeritus professor of politics and history at Emory University, and Haynes is a former historian for the Library of Congress.
This is one of those twisted true-espionage tales that contains many of the elements of a Joseph Kanon spy novel. It also brings home the point that despite the FBI’s efforts, America’s efforts to create an atomic bomb were not among its best-kept secrets.
Get a FREE copy of Kill the Quarterback

Get a free digital copy of Jim Stovall's mystery novel, Kill the Quarterback. You will also get Jim's newsletter and advanced notice of publications, free downloads and a variety of information about what he is working on. Jim likes to stay in touch, so sign up today.