My friend and mentor David Millin ASC made the adventure film
Ride The High Wind (aka
African Gold) in 1965 which tells the story of an aeroplane crash survivor who stumbles on what could be the last resting place of a fortune in Anglo-Boer War gold. After being rescued, he mounts an expedition to the desert with a group of interested people, little knowing that one of them is a killer.

I should just add that by making this, David inadvertently made the first South African zombie movie: the final few minutes show a gun toting half corpse - half skeleton killing someone, so it is the first and so far only SA zombie movie.
www.imdb.com/title/tt0187684