Looking for My Great Great Great Granfather

My great great great granfather came to Australia as a convict. His Chhritine name could be Francis, Joseph, or Alfred. Perhaps he had another name. He had a child to an Aboriginal women, my great great great grandmother. Their daughters name was Caroline Carr from Welbodonga sheep station, NSW.
He owned these people and called them Carr's blacks. I feel that their is some secreatcy because of our Aboriginal history. Would like to know if he had other children. Did he stay in Gamileroi country or did he move to Wellington or further north to the NSW, QLD border. He is a mystery person that needs to be found through a living Carr relative. My great great grandmother married John Richards and they lived at Bengerang of which they owned.
Hoping some one has some information to fill the gaps of our family tree.
Thanks
Caroline Oakley