Property

My grandfather had two sons, one including my father and the other, my uncle. My grandfather passed away a few months ago. My grandmother was soon made to leave that house and settled in with my father. A few months passed and i spoke to my uncle, after having talked to him, i learned that the property belongs to my uncle or so he said. He also stated that your grandfather had left no will and that he had bought the house a long time ago. Furthermore, he even invited me over to see the original documents of the property that are with him. I felt a bit strange about this that how can my grandfather have left his first born son and his wife with nothing. This gave me a reason to thing that there's was something suspicious going on in the family, especially with my uncle, who has covered himself well enough and is trying to dwindle us out. My questions is: that if there's no will who shall be the rightful heir, i also doubt the fact that there was no will as said by my uncle. Please help !