A Swedish home-brew, available as a free PDF download.
Translated from the creator's homepage:
Murder, We Wrote is a social role playing game, made for people who want a bit of role playing on some event of some sort. The game is set on a dinner on a British mansion at the start of the 20th sentyrt, and the host, dr Smith, has just been murdered by one of the attendees. It is the players mission to find and divulge the killer!
Murder, We Wrote won the price for Best Rules in the Dogma contest of 2003.