Considering that the former, well-paid Spanish monarch,

(for insulting whom I risk gaol if ever I return to Spain)
has laundered millions upon millions of dollars
from Panama, Sa'udi Arabia, Liechtenstein, Bahrain...
and banked his cut in Switzerland,
I am wondering what other European royal families
are involved in similar self-enhancing but unpresentable activities.
The Heads of State of Belgium and the Netherlands
are well-known for nefarious activities in the past.
But what of the similarly well-paid monarchs of the semi-
United Kingdom, Norway, Sweden, Denmark (not to mention
the Grand-Duke of Luxembourg and the Prince of Monte Carlo) ? 
I surmise that their elegant but sticky fingers
are (or have been) in stinking pies -
from procurement of teenage children to more 'elevated' enterprise.
The rich have always wanted to be richer.  It has been so
since the invention of agriculture long ago.