The underground Nationaal Steun Fonds (NSF) was of great importance in funding the resistance effort, paying for the care of people in hiding and giving financial support to widows of resistance fighters. The NSF was run by the brothers Walraven and Gijs van Hall. They succeeded in arranging substantial loans with several banks, which were guaranteed by the Dutch government in London. Walraven van Hall was arrested in Amsterdam in January 1945 and shot in Haarlem by a firing squad.
For more information (in Dutch), see the website of the
Instituut voor Nederlandse Geschiedenis.