Although documentation on only twelve episodes of Police Surgeon could be found, producer Leonard White has stated in print that thirteen episodes were produced. And so for years the identity of the thirteenth episode has remained a mystery. But now this episode has at long last been identified: "Diplomatic Immunity." The information was unearthed by Simon Coward of the Kaleidoscope Organisation, who writes that it "was shown 15/10/60 instead of 'You Won't Feel A Thing' which was shown as per its second billing in the TV Times on 29/10/60." The information appears in a publication on which he worked, the Independent Television Drama Research Guide. Oddly, it is the only title in the listing with no cast information, so Simon has promised to rummage through his archives for anything else he can find; he is also in regular contact with Leonard White, and has asked him to do likewise.