A is owner of property and B has taken loan from bank as equitable mortgage

A's cousin B takes the title deed of an apartment owned by A and told that I will give u loan for business from bank against ur property. B takes the title deed and gives it to Bank (as B is saying)for 5 lakhs as equitable mortgage in 2003 year now B is died and A wants to sell this property but he don't have any original documents . Bank also not send any papers regarding any mortgage deed or any agreement between A and B and Bank A gets to know of this 15years later(now). B has not been in touch with A for a very long time. The present situation of documents with A: The electricity bill and Property tax are in the name of A. The Rental Agreement is still in the name of A. A is the owner of flat in all documents Bank not send any single letter from lastb15 year Now B's wife is asking money to repay the loan which was taken by B on against of proprety of A . A wants to sell the property so now what to do. A did not get any loan paper or any letter regarding loan sanction of etc