Buying a property from investor

Dear Sir, I am planning to buy a property (flat in multi-stored apartment) from sleeping investor. The initial information is as below, SALE DEED will have signature of farmer (who agrees to sale land) Builder's signature for developing the project. Since we are buying property from investor, planning to put him as confirmation party. Is it a good practice to put him as confirmation party. Our simple aim is to make sure he should not come tomorrow asking for any foul play. What investor is saying that owner is builder and sale deed will happen between purchaser and builder. However, I (new purchaser) have to pay money to him i.e. investor. Since I am opting for home loan, how can bank pay a cheque to investor who is not owner. For that he said that we will write agreement between builder/farmer/new purchaser and investor as confirmation party. For which I am little bit confuse. But one of the banker is confirmed that this kind of agreement do happen and banks pay to investor. Do you think there is any legal issues involved or how to avoid future issues. THANKS