Richest thieves are probably british monarchy and they DO NOT pay taxes.
The monarch isn't legally required to pay taxes, but the late Queen paid income tax voluntarily, and the King has indicated that he will continue to do so.
Like most of the constraints on the power and person of the crown, the paying of tax is a matter of accepting rules voluntarily, in order to avoid the unpleasantness of having them imposed by force of law.
The British monarchy hasn't stolen anything in the lifetimes of the surviving family members. Of course, the vast majority of their wealth is from land stolen by their predecessors, but mostly that was stolen from other previous thieves.