[Koha] duplicate barcode problem which does not exist in database

Dear All, I am trying to add item in already existing record but it shows item must be unique, while checking for duplicate barcode through staff client we found nothing against that and result shows: "1 result(s) found in catalog, 0 result(s) found in reservoir" But it does not shows any titles/location etc. Please let me know the problem and their solution. Thanking You. With regards, Vinod Kumar Mishra, Assistant Librarian, (Library In-Charge) Biju Patnaik Central Library, NIT Rourkela, Mob:91+9439420860 91+6612462103 (O) email: vinod_librarian@rediffmail.com : mishravk79@gmail.com