лёх (or лох, I'm unsure about the correct spelling) is a word that I heard also among Russians and Ukrainians who never visited Germany. So it's not quite clear whether the German language is the origin. Can anyone shed any light on the origin of this word?

My guess would be it derives from the German word (Arsch)loch (by sound in Cyrillic it would be approx. "арш-лох"), literally for (ass)hole. But if possible I'd like to see some kind of authoritative answer to the question.

I've also heard that German is one of the few languages where most words derive from fecal context, where in other languages offensive terms used in a similar context would be derived from a sexual context. This would actually be an argument for the theory that it derives from German, but again it's more hearsay than anything.