Windsor, Pappalardo, Brooks, Williams and Manley-Harris
Journal of Pharmacognosy and Phytotherapy Vol. 4(1), pp. 6-11, January 2012
This paper shows Australian manuka exhibits significant antibacterial activity as the result of chemical conversion of dihydroxyacetone from the nectar of certain Leptospermum species to methylglyoxal. This is the same process that occurs in NZ manuka honey.
However, there are only two species of Leptospermum in NZ, which is a significantly smaller landmass than Australia, and here there are over 80 species of Leptospermum.
We already know that many Australia Leptospermum honeys have significant levels of activity (equivalent to, or greater than, NZ manuka samples).
And there is currently a large, multi-centre study being undertaken to locate even more sources of active Australian Leptospermum honey.
See: http://www.rirdc.gov.au/research-project-details/custr10_HBE/PRJ-009186