The disappearance of World War II hero Raoul Wallenberg took an even deeper toll on his family than previously thought, his half-sister Nina Lagergren said Monday, confirming a newspaper report that her parents committed suicide. Citing previously unseen family documents, The Wall Street Journal reported that Wallenberg's mother Maj von Dardel and his stepfather Fredrik von Dardel killed themselves by overdosing on prescription drugs in 1979. "That's correct," Lagergren, who turns 88 on Tuesday, told The Associated Press. Wallenberg, who worked as a Swedish diplomat in Budapest, is credited for having saved the lives of at least 20,000 Jews during WWII and averted the massacre of 70,000 more people in Budapest's ghetto. He was recruited and financed by the US and was arrested by Soviet troops in 1945. The Russians say Wallenberg died in prison in 1947, but never produced a proper death certificate or his remains.