At the beginning of September 1969, with the help of eight other people (a local taxi driver, two hairdressing students, a pedagogy student and a family of three
Greek immigrants specializing in sheep farming, as well as another Greek friend of theirs), he organized a fake
consulate general of
Austria in
Wrocław, declaring himself its head. The temporary headquarters of the "consul" was located in the
Monopol Hotel in Wrocław, where he rented a room for half a year under the surname Silberstein, assuring the management that the embassy of Austria would pay for it. He managed to obtain fake seals, prepared for him by an employee of a stamp shop solely on the basis of a Silberstein consul's business card. In the same way, he also ordered official forms from the printing house. He himself made seals imitating the
coat of arms of Austria, using other emblems with a
double-headed eagle. Substantial financial rewards were promised to his collaborators, whom he issued fake documents certifying their appointments as the consul's driver, consulate general secretary, economic
attaché, and so on. In reality, these people were deceived too, as they would lend the fake consul money and provide him with unpaid services. Śliwa/Silberstein, together with the "consulate staff", would regularly travel around Poland in search of further victims. Because of his skills in document forgery and exceptional charisma, he managed to deceive local authorities that started preparing for the opening of a new diplomatic mission, emptying a kindergarten for that purpose. Śliwa/Silberstein also submitted his credentials (poorly written on a torn-out notebook page with a pencil) to the Office of Council of Ministers at the State Council headquarters. His activities were then noticed by the
Security Service, which nevertheless decided to arrest him only after the embassy of Austria protested against the payment to the Monopol Hotel after they were contacted in that matter. Śliwa was arrested for the second time on November 28, 1969. Even after being detained, he demanded to be referred to as Silberstein and claimed to be Austrian (which was quickly disproven, as Śliwa did not understand questions asked in
German). Moreover, Śliwa attempted to convince the investigators that he was a Western spy who was tasked with the creation of an intelligence network consisting of people of Jewish heritage. At the same time, still in custody, he was sending letters to his victims, trying to extort additional funds "to cover attorney fees", all the while maintaining that he was an Austrian consul and the arrest was a mistake. Śliwa did not have a defense attorney. He represented himself and demanded to be referred to as Silberstein the entire time. After a trial lasting only four days, he was found guilty by the Wrocław district court on June 9, 1970, of fraud of over half a million
złoty and sentenced to seven years' imprisonment and a fine of 200,000 złoty (changed to three additional years in prison). Lefteris Conis, who was tried with him, was sentenced for foreign exchange crimes to two years' imprisonment, suspended for five years. Another collaborator, 19-year-old Janina Sikorska (born 1951), received a one-year prison sentence, suspended for four years for presenting false documents. ==Imprisonment and death==