Girlfriend/wife cheated.

I was in live in relation with a girl since 2011.(although we were in love since 2009).this was in full knowledge of the girl's 2014 we married at temple at jammu while we went on vacation.everything was fine.i am from a gud beaurocratic family,while girl is from middle class background.the girl has been of gud character ,deeply engrossed in me.but surprisingly her atitude changed from april 2015.nd got hitched with a guy met online who is of other state.the problem surpisingly here is now she doesn't accepts that she married.also the guy she is involved with is neither listening to me neither girl's family.the girl has completely got disassociated with me.the thing is the only photograph of her wearing sindoor nd mangalsutra was photographed there only by a photographer.nd no negative i hv now of it.but i have all proofs of our visit proofs of her staying wid we stayed in a rented flat just 4kms away from her home.the guy she is contact is not a good guy but as i hv kept it a secret that i was living with this girl nd eventually got married nd all,and now she is out of hands of me nd even her family i am finding it difficult to inform my family.also with this guy she came into cntct via app in dec 2014.i was in knowledge tht she is in tlk with him as a frnd tht meet on social networkng sites.but eventually she met him once in april and two times in june.the thing is this guy is not good and the girl as per my doctor has got hitched to this guy entrapped in sweet talks and she is in acute depression.the thing is as girl is not in her best health and not in anyone's control also gone back to her mom's home.this guy is using her mentally as per his things.he created rift between me and her.and showing adamant behaviour towards me as he knows my loopholes.what can i do to secure my prestige and also my wife's life from tht guy.if i file complaint in police my family will come to know and that too in this particular phase they will not leave girl nd girl's family.and now when girl only negates marriage as she tore the photo nd shifted back to her can i prove my marriage and tame that guy.that guy is not gud luking,neither monetary gud tht she can go about leaving me .