Martin's Aboriginal lineage was revealed to him by his uncle Dean.
'We got talking about family history ... and my uncle goes, ''You know your grandmother was Aboriginal?'',' Mr Martin told Sky News.
Shane has applied for a 'Confirmation of Aboriginality or Torres Strait Islander Descent' with the help of the Aboriginal Sobriety Group.
The group accept he now identifies as being a part of the Ngarrindjeri Aboriginal nation - the traditional Aboriginal people of the lower Murray river in lower central Australia - near modern Adelaide.
Mr Martin understands proving his Aboriginal heritage does not give him a free pathway to citizenship - but his legal team are expected to meet on Tuesday to develop a plan forward.