The series 'Memoirs of an Australian Police Officer' and 'Adventure of an Australian Mounted Trooper' ran in The Australian Journal from 1865-1866. The stories were published anonymously but have been variously attributed to Mary Fortune and James Skipp Borlase.
A note in the 'Answers to Correspondents' column of The Australian Journal 30 September, 1865, p.79 reads: Australian Police Officer: Your tale received many thanks; it will appear in an early number. However the pseudonym did not appear on any subsequent stories. Lucy Sussex believes that the tale referred to is 'The Stolen Specimen' and attributes it to Mary Fortune.
For a full discussion of this series, its authorship and the literary relationship between Mary Fortune and Borlase see 'Whodunit? : Literary Forensics and the Crime Writing of James Skip Borlase and Mary Fortune.'