Brother cheated my father by forging the documents for a loan

I have a problem with my brother on my father's property. Actually we took a loan on his name and the bank and my brother have told my father that he has sign for surety as the land and house was in my father's name. But he has changed the property as gift deed from my father on his name without my father's knowledge. It all happened in 2010 and my father till recently believed that he has given only surety. ONLY RECENTLY WE DISCOVERED THE CHEATING OF MY BROTHER. We have spoken with him regarding this but he refuses to give it back. As we have paid part amount for the loan (paid only through him) and the rest also we are ready to pay. But he is not allowing us to pay and not ready to give back the property. The document is still in the bank as the loan is running. My brother and myself are working in government sector. Now i need consultation regarding how to recover the property.