Threats of false police complaint by my grandfather to my father

My parents and my paternal grandparents are havi verbal arguments since a long time. But since two days the severity has increased. Today my grandfather called the police for a false complaint that my father and mother are a potential life threat to him. My parents didn't even touch him. After a while when my father told him to not involve police, my grandfather revoked the complaint. Basically he had just called to threaten my parents. I believe that he might call the police again someday. But my parents haven't touched him neither have they given any verbal threats to kill him. My father is fearful because he feels police will harass us and demand for a lot of bribe which we are not in a financial position to give. He also fears that my grandfather can easily bribe them because he's rich and police will naturally believe my grandfather's claims as he will act like an innocent senior citizen (age 70). What can I do if the next time he calls the police on these false claims and police