In Biggles in Australia, Harry Larkin was an acquaintance of Sergeant Bill Gilson, a policeman at Broome. Larkin was "an old-timer", probably a prospector like Joe Hopkins. After Biggles' Otter amphibian had been attacked with a spear at Darwin, Biggles asked Gilson if he had encountered any difficulty with the local aborigine population. Gilson admitted there had been a general stiffening of attitude. He recounted a report by Harry Larkin that he had met a party of aborigines on walkabout which had threatened him. At that time, Gilson had not taken the report seriously but thinking about it, Larkin wasn't the type of person who would be easily scared, so the report was something out of the ordinary. Larkin did not appear in the book in person.