Also known as La Decima Vittima, dir
. Elio Petri
This is a far-out (did I just write far-out?) Italian sci-fi movie starring Marcello Mastroianni and Ursula Andress as the prey and the hunter, respectively, in a legalized game of murder. It's from a Robert Sheckley story entitled The 10th Victim (out of print). I managed to find la Decima Vittima for rent in midtown Atlanta (and nowhere else).
This must be the source of Mike Meyers' Ming Tea bit in Austin Powers.