I think his grandfather used to work in the palace and some maharani gave a lot of property to him. That is the story i have heard. But they have build on the property ever since. I do not believe everything they have today is the ancestral wealth. They are few of those people in Nepal who have both the brain and the riches. Then we will have to ask everyone else who worked in palace especially the pujaris to return their property as well, they are filthy rich as well.