Harrased by boy over spurning advances

Dear Sirs/ Madam, I am a father of a 22 yr old Hindu girl who is a student. During her college days got introduced to a Muslim boy by friends circle and they apparently got into a relationship / affair. The affair was of meeting / eating togather sort. The relationship over the period has soured to an extent wherein the girl has refused to be in touch with the boy anymore. In retaliation, he has been stalking, tapping phones, calling all her friends and threatening them. To the extent has gone about stating they were registered married 2 years ago. He is capable of creating a fake certificate knowing Indian government organsations. Need adv on how to bring this to a close and not resort to cheap activities matching the boy.