In 1947 there was concern in the Senate that perhaps the Saudi King Ibn Saud was skimming too much profit off of each barrel of oil he exported.
The US was being charged for oil at the time $1.65 a barrel, 15 cents more than the French.
It appears that at the time the King took some 43 cents for each barrel, but at least one observer felt that he was really skimming far more.
From AP, published November 3, 1947 in the Palestine Post:
Yesterday, oil closed at over $94 a barrel.