It is an Afrikaans reprint of DC Comics' Congo Bill published by Zebra Publications in 1954. The story entitled "Sewe Lange Jare!" is likely the story "Seven Missing Years" starring Congo Bill, translated from DC Comics' original story from Action Comics #146 (May 1950).
Glossy colour cover, 24 pages black-and-white interior.
Cover of Kongo Koot 3 and DC Comic's original cover of Action Comics 146: