Fitzgerald's name in Venona project decrypt 588 New York to Moscow, 29 April 1944, was sent in the clear to Moscow by Soviet Case Officer Iskhak Akhmerov reporting on Elizabeth Bentley's meeting with Perlo group.
The decryption reads, in part, KRAMER[KREJMER][x], PERLO[PRLO][xi], FLATO[FLĒTO][xii], GLASSER[GLAZER][xiii], Edward FITZGERALD[EDUARD FITsDZhERALD][xiv] and others in a group of 7 or 8 FELLOW COUNTRYMENT[ZEMLYaki][xi][c].
After World War II, Fitzgerald resigned from his position with the U.S. Department of Commerce.
In 1954, Fitzgerald was offered immunity from prosecution, which removed the legal grounds to plead the Fifth Amendment.
His alleged code name in Soviet intelligence and in the Venona files is "Ted".