[1] De Groof was then selected to write the background music and arrangement by Helmut Käutner for his legendary guerrilla and anti-war film Die letzte Brücke (The Last Bridge).
De Groof carried on in media and television work until the late 1960s and became known to many directors including Georg Tressler, Rolf Thiele and Rudolf Jugert.
His career ended in 1969 with the theme tune to the programme Der alte Richter[3] starring Paul Hörbiger.
Carl de Groof found that he had multiple sclerosis at the beginning of the 1970s, which forced him to stop composing.
Later in the same decade, he retired to Spain, where he spent his remaining years in the hope that the sunny climate would slow the progression of his condition.