GPA for Signature in Sale Deed

Hi Gurus of Law, I have a Query on GPA given for registering a property. Below are the case details, Please let me know whether this property is marketable. Mr A, Mr B & Mr C are layout owners and have sold to MR N. MR N has given GPA for getting the land register in his name to Mr V. Mr A,Mr B & Mr C have registered the Property in the name of MR N in the year 1992 on the basis of GPA and Mr V has signed on behalf of Mr N as Mr N was out of Country. Now Mr N has sold this property to Mr R in the year 2004. The Sale Deed does not mention anything on the GPA. Was Mr N legally eligible to sell to Mr R?. Mr R is now selling the property to me. The catch is nor Mr N or Mr R has a copy of the GPA & they have lost it. I have procured the loan on the property. The Bank legal department had queries on the GPA. After confirming this, they have cleared the loan. Is Bank legal department correct in ignoring this GPA.?. Are there any Legal Issues if I proceed with the Property?. Please let me know whether the Property is marketable title. - Ashok Shroff, Bangalore