The USCIS will generally issue you a Notice of Intent to Revoke (NOIR) which will give you the opportunity to present documentary evidence of the bona fides of your engagement. Be prepared to provide a significant amount of information to prove up your relationship. If the USCIS affirms their decision, your fiance will then re-apply for the K-1 visa.
Answered on Oct 19th, 2011 at 2:29 PM