Inspector J.J. Tholen is a fictional police detective of the 1950s Amsterdam Police, appearing in Winston Graham's thriller The Little Walls where he is in charge of investigating the mysterious death of the main protagonist's brother.
Tholen (the full first name is never given) is polite, soft-spoken (in not-quite perfect English) and highly professional. Like the proverbial Dutch Uncle, he is able to act firmly to protect the protagonist from irresponsible impulsive acts which may have resulted in injury or death.
In one passage, a Dutch prostitute who had been interrogated by Tholen complains that "since the war [i.e. the Nazi WWII occauption], our police had learned too much from the Germans". However, in no scene where Tholen directly appears does his conduct bear out such accusations of brutality.
Touching on sensitive issues of foreign relations and national security, Tholen works closely with the aristocratic diplomat Van Renkum, who is related to the Dutch Royal Family and seems - though is never explicitly stated to be - involved with his country's security service.
A Dutch character created by an English writer and seen throughout through the eyes of a British protagonist, Inspector Tholen can be said to represent the perception of the post World War II Netherlands in British eyes.