>Interest on an investment loan for an income producing purpose is fully deductible if the income falls short of the interest payable. The shortfall can be deducted for tax purposes from income from other sources, such as the wage or salary income of the investor.
Edit, better link: https://en.wikipedia.org/wiki/Negative_gearing#Australia
>Interest on an investment loan for an income producing purpose is fully deductible if the income falls short of the interest payable. The shortfall can be deducted for tax purposes from income from other sources, such as the wage or salary income of the investor.