Income tax query

I bought a property in 2003 on cash payment of Rs xxxxx though sale deed. This sum was payed through personal savings accrued over time( 2-3 years) from withdrawls from bank which were kept at home. Now Income Tax has asked to prove source of fund of this property. My IT return for assessment year 2004-05 too reflects that i had an income from salary much more than the amount for which i bought the property and i had a bank balance more than xxxxx purchase price at the time of buying property. Please guide how to answer the query from income tax.