Can a sponsor wife stop immigration from giving her husband permanent green card?

If the wife really believes that the marriage is not bona fide, she can just not petition for him or not support his application. If he already has a green card, it may be too late but she can still notify the USCIS if she truly believes that he only married her for the green card.

Establishing fraud is not as easy as making assumptions like those presented in the inquiry. While the facts of any particular situation may lend themselves to the potential that some type of fraud occurred, the US government needs "clear and convincing evidence" to establish fraud once it has occurred and once a foreign national has obtained lawful immigration status as a result of the fraud. Having had this situation come across my desk from time to time, the best I can tell you is to sit down and speak with an immigration attorney who can provide a realistic explanation as to whether the government will be interested in pursuing a claim of fraud in your situation. I am certainly a firm believer that fraud must be punished whenever and wherever it is found because it is unfair to those who do things the right way to permit folks who lie their way through the process maintain status that they obtained via a lie. But getting the government to take action is the key and the government moves slowly in situations like this. CIS has a Fraud Detection and National Security unit that is supposed to handle cases like this, but it has been my experience that aggressive representation is the way to make these issues get resolved. So I would recommend scheduling an appointment with a knowledgeable, licensed and competent immigration attorney who can assist you in determining whether the matter is worth pursuing. Good luck.

Not enough information is given to really be able to answer your question. You, if you are not the spouse, cannot do anything. It will be up to your daughter. She needs to contact an experienced immigration attorney for a face-to-face consultation and give him/her all of the facts surrounding her situation. He/she would then be in a better position to analyze her case and advise her of her options.

If your daughter has filed the immigration petition for him, she can withdraw by writing to the USCIS. If she has not filed the paper, simply does nothing and he will not get a green card.

If she decides to withdraw her petition she may do so. Presumably she would also want to file for divorce.

You could complain to the immigration service. Ultimately, it's their decision whether to pursue the matter.

Yes, you would have to file to revoke the relative petition with USCIS. Our law firm has handled such cases if you would like assistance.