Claus Helberg (31 January 1919 – 6 March 2003) was a Norwegian resistance fighter and mountain guide,  was a member of Company Linge, a resistance commando unit that was best known for carrying out, during World War II, which titled series of operations undertaken by Norwegian saboteurs during World War II to prevent the German nuclear weapon project from acquiring heavy water (deuterium oxide), which could have been used by the Germans to produce nuclear weapons?