Saw this movie on tv years ago. A young man is recruited by an older man to find an ex-nazi, this takes place overseas, could be Germany, but right after the war when food and things are scarce. I only remember two scenes. In the first the young man is have a bowl of soup at a restaurant, and the suspect looks at the bowl and goes “Meow,” making the joke that the soup was made from an alley cat. When the young man is upset, the suspect who is older explains he really didn’t mean it. In the second scene, the youg man is reporting to his older handler, that he has doubts that the suspect is the ex-nazi, and that he is fond of cats. The handler upbraids him that Goebbels was fond of this, Himmler was fond of that, and that Hitler was fond of music. So what?
Have you tried The Boys from Brazil? I don’t think it’s the film your looking for, but…