nina viveka maria lagergren ("née" von dardel; 3 march 1921 – 5 april 2019) was a swedish businesswoman. she was the half-sister of raoul wallenberg. she was known for her trying to find out what happened to him after his disappearance. she was the founder of the raoul wallenberg academy. she also presented the radio program "sommar i p1" in 2014.