World War II Database

Raoul Wallenberg arrived in Budapest in the guise of a diplomat to help Hungarian Jews escape the Holocaust. When Soviet troops captured the city in early 1945, he was arrested on the suspicion of being a spy. Some time after being transferred to the Lubyanka prison in Moscow, Russia, he disappeared and was never seen again. Although generally agreed to have died in the Soviet prison system around 1947, he had officially been regarded as a missing person. In 2016, the Swedish Tax Agency, in charge of registrations of births and deaths in the northern European country, officially declared him dead. The date of death was set as 31 Jul 1952, five years after he had definitely disappeared.

For more information:
New York Times: Sweden Declares Hero Wallenberg Officially Dead
WW2DB: Raoul Wallenberg