I haven't read many of Georges Simenon's Maigret books, but I recently read (and enjoyed) Maigret and the Ghost. I had no idea how many Maigret books there were until I read this New Statesman article (thanks B for alerting me to this). In fact, the article states that there are 75 of them and that Penguin are re-publishing them all, re-translated, at the rate of one a month.
I particularly liked the bit towards the end of the New Statesman article, to the effect that a number of the Maigret books were translated into English by Geoffrey Sainsbury. It seems that Sainsbury took some liberties with his transactions, often altering details. Nevertheless, his translations "were duly submitted for
the author’s approval, which was always forthcoming. And for good
reason: Simenon did not understand a word of English.”
Even though the New Statesman article says that Maigret is one of the few detectives in literature who is possessed of characteristics not shared by their creators, it seems that in one this respect, Maigret is similar to Simenon: In Maigret and the Ghost, the point is made that Maigret speaks hardly any English.
EDIT - I am uncertain if I've previously posted this item. I thought I had, but when I edited it to add an additional label, blogger posted (or reposted?) it under the current date. This has left me unsure of the position, so I'm putting it here.
FOOTNOTE: I now see that Simenon lived and worked for some years in the USA. This seems to throw doubt on the statement that he didn't speak much English!