You inspired me to look it up. Here's a little blurb about it from Google:
The greatest and most recent theft of Aboriginal identity was by Leon Carmen, alias Wanda Koolmatrie, author of the book My Own Sweet Time. In March 1997, Leon Carmen, a 47-year-old white male, admitted he had invented the persona of Wanda Koolmatrie, allegedly a descendant of the Pitjantjatara people in South Australia and a member of the stolen generation.
Source