Mortgage for borrowed money
(1) You can deduct expenditure you incur to discharge a mortgage that you gave as security for the repayment of money that you * borrowed if you used the money solely for the * purpose of producing assessable income.
Mortgage for property bought
(2) You can deduct expenditure you incur to discharge a mortgage that you gave as security for the payment of the whole or part of the purchase price of property that you bought if you used the property solely for the * purpose of producing assessable income.
Money or property used partly for that purpose
(3) If you used the money you * borrowed, or the property you bought, only partly for the * purpose of producing assessable income, you can deduct the expenditure to the extent that you used the money or property for that purpose.
No deduction for payments of principal or interest
(4) You cannot deduct payments of principal or interest under this section.