On Saturday, 5 December 1953, Józef Światło reported to the American authorities in West Berlin. He was a high-ranking functionary of the Security Office. For several months the communist authorities in Poland did not believe in his escape.

Izaak Fleischfarb, or later Józef Światło, was born on 1 January 1915 in Medyń near Zbaraż as the son of Gabriel and Rebecca. His father was an employee of the local mill, and his mother was responsible for raising five children. The family moved to Kraków, where Izaak completed primary school and then began working as a shoemaker.

In the 1930s, he became involved in the Communist Union of Polish Youth, which sent him into prison for anti-state activities. In 1939 he was mobilised into the army and took part in the September campaign. He escaped from German captivity to the part of Poland occupied by the Soviet Union. There he was exiled to what is now Kazakhstan and there, in April 1943, he married Justyna Światło, taking her surname.

In May 1943, he joined the ranks of the army formed by the Polish communists in the Soviet Union, from where, in autumn 1944, he moved to the newly formed security apparatus. Here, he quickly climbed the career ladder and became a deputy provincial head of the Security Office (UB) in Warsaw, Olsztyn, and Krakow. During that time, he took part in arresting soldiers of the Polish independence underground, personally conducting interrogations combined with brutal torture of detainees. He took part in the plot to falsify the results of the June 1946 referendum and the January 1947 Sejm elections by the communists. In 1948, he became deputy director of the Special Bureau, and then of Department X of the Ministry of Public Security (MPB), which conducted investigations into Polish communists.

Światło enjoyed the full confidence of the then highest Polish authorities, as well as the Soviet security apparatus, headed by Lavrentiy Beria. However, while on official business in Berlin, he moved to West Berlin on 5 December and surrendered to the Americans. In the autumn of 1954, a series of broadcasts featuring him on the crimes committed by the Communists in Poland began on Radio Free Europe.