Daughter in law blackmailing boy and his family

Hi, I happened to know well educated business class family. The mother in law is 55 years old and my father in law is 65 own a small business. Boy is 26 years old and get married 1 year back and His family beared all the expenses of the marraige. Since marriage his wife is taking care of her family financially. After 2 months of marraige she abused his mother and father and has posed false claidemands to the his family threatening them to get them arrested under the dowry act.incidentally ,they havent received or demanded even a single penny in the marriage. Then after 4 months she again created an issue left home and claimed boy and his family said her to leave that house then after 1 week every one sat down to rsolve former issue then she again posed false eligation that boy,elder Sister hits her and demanded money from her and Her mother came to our house and threatened boys family that they will file complaint that they are torturing their daughter under the dowry act but after that everything get sorted. again after 2 months she created an issue. Hits her husband , break things at boy house used abusive language toward boys family hits her mother in law and left home. so boy called her family and her mother again posed false claim that they will file compalint that in laws are trying to burn their daughter for dowry. AFter 2 days She is again threating her husband that she will commit suicide and her family is also harrasseing boys family that they will file complaint. Ehat can be done in this case. Please suggest.