Court held that the assessee in order to cover the cost of interest payable to the creditors for the unpaid period, invested the surplus in fixed deposits and earned interest. The amount earned by way of interest was paid to the lenders and creditors. Thus, there was a nexus between the interest paid to the creditors on the unpaid balance and interest earned on the deposits. The interest expenditure was incurred wholly and exclusively for the purpose of earning the interest income and therefore, the assessee was entitled to deduction of the interest income under section 57(iii) .( AY.2005-06, 2006-07)