Using IP redraw for IP interest payments

Hi to all
I am just about to finish the refinancing of my IP, and currently have some $50000 of extra repayments I have deposited into the IP loan. My question is though, since this new loan is going to be interest only loan, can i pay the interest at the end of the month thru the redraw facility that I have available in the loan. ie. would the tax office be ok with this.

eg. $90,000 loan balance (with 50000 redraw available)
I pay $400 pcm interest which comes out of the redraw, so loan would then become 90,400 the following month and then interest calculated on that, and so on...

In theory, I am not using the redraw facility for private purposes ie holiday car etc, and the redraw is being used to service the loan, so why should the tax office be questioning it? It just saves me using $400 of my own money which I could use effectively elsewhere.

Any help would be great.
Should be ok from a tax pov, but check with your lender - you may have to actually withdraw the money and then pay it in again or they may class it as a missed payment (even tho you have paid in advance)