As Sweden's envoy to Hungary during the war, Wallenberg prevented the deportation of 20,000 Jews to Nazi concentration camps. He also talked occupying German officers out of a plan to obliterate Budapest's Jewish ghetto.
When the Red Army occupied Hungary at the end of World War II, Soviet intelligence abducted Wallenberg. The Soviet Union claimed that Wallenberg, who was incarcerated at Moscow's Lefortovo prison, died on July 17, 1947 of a heart attack. Later reports indicated that he had been executed.
Wallenberg's fate remains one of the great unsolved mysteries of World War II.
Now, the archives of the Federal Security Services say a man identified only as Prisoner No. 7, who was interrogated on July 23, 1947, six days after the diplomat's reported death, was "with great likelihood" Wallenberg.
Russia reported the findings in November to members of a research team that conducted an investigation into Wallenberg's disappearance in the 1990s.
The researchers, Susanne Berger and Vadim Birstein, informed Wallenberg's relatives of the findings in a letter that was released for publication on April 1.
-- Brian Whitmore