Tarzan and the Kawana Treasure (1975)

The famous scientist, Professor Parker, and his daughter, Caroline, arrive at a port in Equatorial Africa. There, they enlist the help of Jack, an unscrupulous adventurer only interested in profit, to lead an expedition into the depths of Africa and uncover the secret of longevity of a recently discovered tribe: the elusive Kawana. In principle, their objective is scientific; but, in reality, what they are truly after is to seize the enormous diamonds hidden in the isolated territory of the endangered community. Now, apart from the ferocious natives, the team has one more problem to deal with. Can they escape the fury of Tarzan, the mighty lord of the jungle?