Girl's parents are not agreeing to the Nikah done

LI've create marriage affidavit with help of local advocate. we both are Muslims and have done nikah. My parents knows about it but girls parent don't know about the marriage. First we are to wheedel girls parents for our normal marriage but they are not agreeing. So i think that i call my wife and ask her to come to nearest police station and inform them that parents are not agreeing and they want girl to marry another man. i have not registered marriage in my ward. that is court marriage is not yet done. I've only proof of nikah and affidavit with girls signature on it saying she's with me. what are the consequences that girls parent can do with help of police to take her back to her home? or can they file a case against me? I don't want to be molested by local police authority as parents can give them money.