In the first series of Flikken (1999), Turkish actors Cahit Ölmez and Kadèr Gürbüz star as brother and sister Selatin and Mihriban Ates. In one episode, they are talking about something in Turkish. While Kadèr Gürbüz has a Turkish father, her mother is Flemish and therefore she cannot speak Turkish. Before the shooting of that particular scene, Cahit Ölmez had to teach her how to say each and every word of her lines.
The character John Nauwelaerts played by Jo De Meyere first appeared in '"Heterdaad" (1996)'. He swapped series because the character moved from Brussels to Ghent.