Using records from Dutch and Czech archives, the author attempts the first-ever reconstruction of the case of Jan Adriaanus Louwers, a Dutch businessman, who became a victim of the Czechoslovak Communist regime’s efforts to compromise citizens of Western countries. Louwers spent time in Czechoslovakia even before the Second World War. After the war he returned as the representative of a Dutch manufacturer of synthetic fi bre. He was arrested in December 1949, and accused of a number of serious crimes, including economic and military espionage, smuggling hard currency, and assisting in the illegal emigration of people whom the regime considered suspect. On 2 March 1950 he was tried in the State Court in Prague, together with nine Czechoslovak citizens, who had allegedly formed an organized crime group with him. (Another three were tried in absentia.) Josef Urválek, the infamous public prosecutor, sought the death penalty for Louwers, but he was ultimately sentenced to fi fteen years of forced labour. The trial was also aimed against diplomats of the Netherlands Embassy in Czechoslovakia, who had, according to the public prosecutor, helped Louwers to spy by providing him with a diplomatic pouch for sending his information; some of them were later expelled from Czechoslovakia. In addition to discussing this trial, the author describes in detail the efforts of Dutch diplomats to get Louwers released, which they managed to do a year later. Louwers, according to the author, represented for the Czechoslovak authorities a suitable subject on which to demonstrate the hostile intentions and depravity of the West.