The Algerian Liberation Front was supported by the Trotskyist Fourth International during the war against France (1954-1962). The Dutch Secret Service followed members of the Fourth International Secretariat, which had settled in Amsterdam in 1958. An infiltrator from the Secret Service betrayed the initiative to produce false French francs in a printing shop across the German border. Arrests took place in this printing shop in the summer of 1960. The papers of one of the International's members, the Dutch writer Sal Santen, were confiscated. Among these papers was a letter from the printer that detailed his demands. The letter was dated 27 January 1960, and concluded with: 'We cannot afford any indiscretion in this matter.' Sal Santen was given a prison sentence of 15 months for incitement to counterfeiting.