In rare cases, USCIS schedules an interview to remove the condition from a marriage-based green card. This is to determine if the marriage is real and ensure that there is no immigration fraud in obtaining a green card through marriage.
USCIS asks questions to check if:
the parties to the marriage are in a genuine relationship ;
the foreign national is being truthful or lying about an important fact to obtain a green card.
The foreign national paid any money to receive the green card;
Marriage Fraud
The I-751 interview allows USCIS to inquire into the circumstances of the parties' life and investigate deeper into suspect cases.
A decision may be withheld for a thorough investigation when necessary.
It is therefore very important to present a well-prepared packet and answer all interview questions the officer asks.
Standard of proof and appeal
USCIS frequently mixes up the absence of marriage bonafides with proof of fraud.
However, this distinction is subtle.
The finding of marriage fraud is difficult to overcome, and it is, therefore, necessary to have a well-documented case.
An appeal against marriage fraud denial can be filed before the Board of Immigration Appels (BIA).