Grandparents gave property to father through will siblings want share

My grandparents wrote their will and gave all their property(old house) to my father. My father & mother demolished and built shops and house on the same land. Now my 4 aunts and 1 uncle (they all are settled and live separately with their families) are pressuring my father to divide the property which my father doesnot want, as he had paid all money to built the house.Since the will and registration of house is in my father's name, my relatives are putting false complaints in police station, in women's counsel against my father. Please advice to stop this everyday torture by my relatives.