The embassy was seized by a group of four Polish exiles, led by a former employee of the Służba Bezpieczeństwa (SB) security service, Florian Kruszyk.
After seizing the embassy and taking 14 hostages, the group made several broad political demands including the abolition of martial law in Poland.
After intensive negotiations, a Swiss elite Stern anti-terror squad raided the embassy, freeing the hostages without a shot being fired.
Negotiations, headed by the then Bundesrat Kurt Furgler and also aided by Dominican Józef Maria Bocheński, took place over the course of 35 recorded phone calls.
[1] On September 8 at 10:15 pm, the Federal Council convened as a whole and agreed to give the head negotiator Furgler carte blanche to unilaterally decide whether to raid the embassy premises with special forces.
[5] On September 9 at 10:39 am, a policeman in plain clothes dropped off either multiple boxes or a food basket[7] at the embassy doorstep, purportedly breakfast for the occupants of the house.
Seconds later, after an initial failed detonation, the petard exploded and units of the Stern elite antiterrorist squad raided the embassy.
[5] The group leader, Kruszyk, had served a nine year sentence in Austria for the 1969 armed holdup of a Viennese jewelry shop, during which he held the jeweler's family hostage, which lead some experts to believe that the seizure had been financially rather than politically motivated.
[2] It was revealed in 2013 that around the time that the rescue operation occurred, members of the Federal Intelligence Service of Switzerland violated the Vienna Convention on Diplomatic Relations and illegally entered the embassy, seized diplomatic documents, brought them to the nearby federal prosecutor's office, photocopied them, and then returned them to the embassy.