Missing inheritance

My father is already deceased. He was receiving an inheritance from her deceased Sister in the USA. Before my father died he informed us that there are lots of properties still needed to be distributed from them (brothers & sisters) and was actually been handled by one of the siblings in USA. My father received a few amount and that's it, before he died my father informed us that there are still 3 properties sold and to be distributed to them, from then on we never received anything from my uncle (w/c normally they put in my father's bank account). We don't hold any copy of the inheritance since my father binded with my uncle by trust. What are we going to do? Is it possible to sue our uncle or we are just going to waste our money and time?

have you tried communicating with your uncle?

ok.. We will try to locate his whereabouts and communicate with him. But it's getting harder and harder to find him. He's coming back and forth from the US. We don't know if he is deliberately ignoring us. But according to my mother during my father's funeral our uncle informed her of the said sale of 3 properties in US to be distributed to the siblings. But after that he never showed up.