StB's Technical Directorate gave Frenzel many new and experimental devices, including a small film-carrying statue, which, by way of a small explosive charge, would destroy its film unless a special mercury switch was deactivated. Much of the information the StB gathered from Frenzel was passed on to the KGB. Downfall In September 1959, Frenzel was passed on from Molnar (who was promoted to deputy director of the StB for his work with Frenzel) to a new controller, a man operating under the pseudonym Franz Altman. Altman's favourite method of transporting information and film was by way of the containers that would destroy their contents, such as the small statue mentioned before. These containers would be passed on to Czechoslovak diplomats, who would return the information to Prague. However, in October 1960, the West German counterintelligence organisation, the BfV, became suspicious of Altman, after the tax department reported spending disproportionate to his income. Altman was arrested just before he boarded a flight to Prague. The arresting BfV agents went through his luggage, and found a talcum powder tin. It was determined to be carrying film, and BfV agents very carefully disassembled it. Inside was a roll of film, and when the film was developed, photos were found of key West German installations. In the corner of one photo was the number plate of a car. The BfV investigated this, and found that the car belonged to Alfred Frenzel. Along with further evidence, he was arrested and sentenced to 15 years in prison. He was exchanged for four West German agents five years later. Frenzel died of natural causes in 1968. References The Ultimate Spy Book by H. Keith Melton, 1899 births 1968 deaths Czechoslovak spies against the United States Czechoslovak spies against West Germany Social Democratic Party of Germany politicians German Bohemian people People of the StB People convicted of spying for Czechoslovakia