My husband's naturalization process has been denied.

Hi I am a naturalized citizen and we married in 2001. We had our first child in 2002. My husband toke the test for nationalization I think in 2008-2009. He passed all the questions and the written part and we waited for oath ceremony. The migration office finally answered us requesting more older tax returns from 2002 when he came to USA. We submitted all paperwork and they finally answered us after a while stating that he's under investigation . Later in 2012 we were traveling and asked if it's okay if there were going to be appointments soon, they said none. We traveled and came back waited and no response so we went in person . We asked them what's delay they stated now been transferred to green card investigation. He has been in USA since 2002 with his alien card . We finally got notice last winter 2016 stating that the affidavit of support from a friend of ours stated he never had done affidavits before and he has and that this was fraudulent and therefore disapprove my husbands naturalization. The gentleman filled the paperwork and gave them to us we were not aware if he has had affidavits done for others before. Is there also a problem now with his permanent residency ?