Who is Francois du Toit from When the Lion Feeds and what is their importance?

Francois du Toit is an old friend of Dufford Charleywood's, Francois du Toit is a small man with a round brown face and a moustache reminiscent of the whiskers of a fox terrier. He wears a derby hat, pulled down hard to his ears, giving the overall effect of a dapper little man. Francois and Duff work the diamond fields together and Duff saves his life when he pulls him out of a cave in after the rocks break his legs.