Medicare Proof Doccuments

Hello, I have moved to Australia and am looking to apply for a Medicare card. It implies on the their website that they require documents from another country and that they have to be "certified" documents. I am found that most documents are being emailed these days in NZ and I don't have "official" copies. Did anyone here have to have present "certified" copies when you applied at the medicare office or any problems with presenting a printed copy? Did you have to go and get them witnessed by someone ? Thankyou