The tyre is de-laminating. Sometimes it happens on the sidewall, most often on the tread section. I have had this happen to a spare in the boot! Don't drive on it, worst case it can blow, best it will just vibrate. It can not be repaired. Let me know if you need a tyre shop, I will probably be able to give ypu details of some decent places, depending on whereabouts in Melbourne you are.