In laws have kept my wife hostage and torturing her what can i do

We did court marriage on 9 december 2016 against the wish of my wife's family members without informing them, and planned to do social marriage on 17 january 2017, during this period my wife stayed back at her paternal home with her family, but some how her parents came to know about this and since then they are torturing her physically and mentally. they kept her like hostage and ceased her mobiles, i do not have any means of communication with her. she left one letter outside her home (we planned this earlier if something like this happens she will leave one letter stating the situation) and as per that letter they are beating her like hell and pressurizing her to quit the court marriage. even her father told he will send me to jail. now she is worried and to keep me safe from her parents she is even willing to call the marriage off. what should i do kindly suggest. anonymous