k-1 disqualifier?

I hope someone can answer this for me. I have already researched on USCIS Home Page, but there isn't anything on my specific problem. So here goes:

When I was younger and not much of a planner I tried to help a friend obtain citizenship through a fraudulent marriage. I didn't realize the severity of my actions until we had our interview with INS. At that time I realized how wrong my actions were. I then confessed my wrongdoings before any real damage could be done i.e. no charges were filed and I was able to walk away from a truly stupid idea. Years later while out of the country I met someone and we fell in love. I am now back in the states and wish to bring my fiance here. Will my past mistake automatically disqualify my k-1 application? If so are there grounds for an appeal? Would it be better to have an attorney handle it at that point? Thanks and any help is much appreciated.