"Heart of Darkness" is based on Leopold's Belgian Congo.
More recently, there were the child sex murders of Marc Dutroux, which were covered up for years by the Belgian authorities. Probably a lot of Belgian politicians were involved with Dutroux's activities, participating in some sort of child sex ring. It's hard to find any other explanation for why the case was handled the way it was.
People should also read Adam Hochschild's "King Leopold's Ghost" regarding what happened in the Belgian Congo.
Dr. Belien does go into painful detail about the Dutroux case in the book - it's ghastly.