Borrowing money from overseas to purchase in Australia

I am looking to finance a AUD $12M real estate purchase in Australia and 
was wondering if I am restricted to obtaining finance from an Australian 
Bank?

I live in Australia and have both Australian and British citizen****p.

Australian interest rates are closing in on 10% however US interest rates 
are considerably lower so the obvious question is how does one benefit 
from the lower interest rates available overseas?

Thanks in advance...