working with fake degree certificates by stolen and not responding

Hi Team, my brother prepared fake diploma certificates by stealing my certificates when he was stayed at my home. Earlier also he was dismissed from college for doing the same i.e making principal signature forgery on hall ticket. He caught by principal and dismissed. Now he is having multiple college certificates and doing job. When I came to know, I asked him return my certificates back, instead of returning my certificates he is threatening he will give false information to police that I made those certificates for him and ready to spoil my life. When i made a complain in police station, they did not prepare FIR. The police saying they will call him and inform to me later. But still he was not responding and they are also not doing any further procedure . Please help me how to proceed. Thanks in advance Ramana 9885996978