A document signed by Swedish diplomat Raoul Wallenberg that saved a Jewish woman from the Nazis sold at auction for more than £10,000 ($13,000).

On Sept. 22, 1944, an affidavit signed by Wallenberg in Nazi-occupied Budapest saved the life of Zsigmondne Simko, a Hungarian Jewish woman, by declaring that she was under the protection of the Swedish government.

The document was purchased on Thursday for around £10,000 ($13,310) through the Nate D. Sanders auction house in Los Angeles. In keeping with company policy, Sanders did not divulge the identity of the document’s seller or buyer.

Bidding for the “protective” certificate or passport, which exempted the bearer from forced labor or wearing the Jewish yellow star, started at $8,000 and attracted three other bidders, besides the winning collector.

Wallenberg, the scion of an aristocratic Swedish Lutheran family, was sent to Budapest in July 1944, through the joint efforts of the U.S. War Refugee Board and the Swedish government, the latter appointing Wallenberg as First Secretary of its embassy in the Hungarian capital.

With no previous experience as an organiser, the 32-year old Wallenberg established a network of hospitals, nurseries and some 30 “safe houses,” and issued a stream of “protective” passports and papers to save an estimated 15,000 Jews from almost certain death.

When Russian armies forced German troops to abandon Budapest in February 1945, the new occupiers arrested Wallenberg as a suspected spy and he is believed to have died in a Soviet prison around 1947.

Yad Vashem, Israel’s Holocaust memorial authority, officially recognised Wallenberg as a “Righteous Among the Nations” in 1963.