There are no known pre-European contact between Australian Aboriginals and New Zealand Maori. In fact there are no evidence of any contact between the Indigenous Australians and other Polynesian peoples at all. The Polynesians originated in Taiwan around 3,000 B.C., and quickly swept through Polynesia, arriving at New Zealand around A.D. 1,200. The Aborigines on the other hand arrived in Australia 50,000 years ago.
An important thing to note here is that the Polynesians expanded east by chain hopping through the islands, and then made a downward hook to New Zealand from around Tahiti. That is to say, the path of New Zealand's first Maori settlers did not take them through Australia. Refer to the map below for an illustration.
(Click to enlarge - shamelessly stolen from here.)
While Australia is not as far from New Zealand as the latter is from Tahiti, the ancestors of the Maori found a relatively vast virgin land when they reached New Zealand. There would have been no more population pressure to migrate further, as had been the case in the much smaller islands of the Polynesian heartland. Due to their self-sufficiency, and with New Zealand being too isolated to maintain contact with the homeland, the Maori also ceased long range travel altogether.
Another thing to note is that by the time the Polynesians began exploring the Pacific, the early Australians have inhabited their continent for tens of thousand of years. While there are evidence of more recent cultural contact, for example the introduction of the dingo to Australia (perhaps 10,000 to 5,000 years ago), nothing is known about any such relations. Hence, when early Polynesians reached Melanesia, they found it already occupied, and moved along eastward, thereby missing Australia altogether.
The first recorded instance of Maori presence in Australia dates to the 1790s, when some chiefs began visiting Sydney. It was a start of a budding commercial relationship and they befriended Samuel Marsden, an early missionary to New Zealand. They, or other chiefs in subsequent visits, may well have met Aboriginal Australians.
Unfortunately, 2,000 kilometres is no small distance. Europe also lost all contact with Greenland.