I've found this knife at
http://www.collecteez.com/
with the following comment:
CORVO KNIFE
Chile , 1971, made by Famas - a governmental manufacturer, overall length (up to the center of the arch) 12" (31cm).
The Corvo is a unique dagger/knife which represents a national symbol in Chile . In its shape it imitates the work-tool of mine workers, and also the claws of the Andes' bear. There are two basic kinds of Corvo, one that which very bent and one which is less. The very bent kind is bent in almost 90° and is issued for the commando forces. A regular commando Corvo is black and has a plastic handle with plain leather sheath.
It looks like the above posted "keris", especially the scabbard.