The Duquesne Spy Ring

The Duquesne Spy Ring

How’s this for being a step ahead of the enemy? Before America ever fired a shot in World War II, we had rolled up a massive ring of Nazi spies operating on U.S. soil—33 in all, ranging from Paul Bante to Bertram Wolfgang Zenzinger. By December 13, 1941—just six days after Pearl Harbor—every member of the group had either pled guilty or been convicted at trial, including its ringleader Fritz Duquesne.

Frederick Duquesne

It all began when a lone German-American refused to give in to Nazi aggression and hatred. His name was William Sebold, and he served the Allied cause by becoming a double agent for the FBI.

Sebold was a naturalized U.S. citizen who worked in industrial and aircraft plants throughout the U.S. and South America after leaving his native land in 1921. During a return trip to Germany in 1939, Sebold was “persuaded” by high-ranking members of the German Secret Service to spy on America. Sebold received espionage training in Hamburg (including how to work a short-wave radio), but not before secretly visiting the American consulate in Cologne and telling officials there that he wanted to cooperate with the FBI.

We were waiting when Sebold returned to New York City in February 1940. He’d been instructed by the Nazis to take on the persona of “Harry Sawyer,” a diesel engineer consultant. He was then to meet with various spies, pass along instructions to them from Germany, receive messages in return, and transmit them back in code to Germany.

With Sebold’s masterful acting, we played right along with the ruse, using some deceits of our own.

Agents secretly filmed the many spies who passed through Sebold’s bogus office.

First, ourI Lab engineers built a secret shortwave radio transmitting station on Long Island. There, our agents pretending to be Sebold sent authentic-sounding messages to his German superiors for some 16 straight months. Over that time more than 300 messages were sent and another 200 were received from the Nazis.

Second, we helped set up an office for “Harry” in Manhattan where he could receive visiting spies. The office was outfitted with hidden microphones and a two-way mirror where we could watch and film everything going on. With cameras secretly rolling, Sebold met with a string of Nazis who wished to pass secret and sensitive national defense and wartime information to the Gestapo.

One of those visitors was Duquesne, a veteran spy who served as the group’s leader. In Sebold’s rigged office, Duquesne explained how fires could be started at industrial plants and shared photographs and plans he’d stolen from a plant in Delaware describing a new bomb being made in the U.S.

Sebold talks with Duquesne, who was unaware that FBI agents were taping the whole episode behind a two-way mirror

Another one of the spies, we learned, was preparing a bomb of his own and even delivered dynamite and detonation caps to Sebold.

Once we had enough information to pinpoint the members of the ring and enough evidence for an airtight case, the 33 spies were arrested. Nineteen quickly pled guilty; the rest were found guilty at trial in the days following the Pearl Harbor attack.

As a result of the massive investigation, the FBI—and America—entered the war with confidence that there was no major German espionage network hidden in U.S. society.