Forgive me, I don't know if you are hinting or if you already know.
Art collections are a means of transferring wealth. They transfer art between collections at whatever the cost of their real world transaction (art can be worth whatever you say).
Sell some kids, influence, favor etc… Transfer a painting between private collections. It can be worthless garbage, no matter. The buyer pays for the artwork, and the only paper trail is that Private Collection 1 bought a painting from Private Collection 2. The only crime they can be accused of on the paper trail is having shit taste in art.