6 Whether the share of the reward awarded to Noble and Owens was paid over, if at all, to Victoria or to Queensland has some consequences for the cause or causes of action on which the plaintiffs seek to rely in these proceedings. An identifiable fund of reward money as such may never have existed at all, as distinct merely from a promise to pay a reward from government funds in the event that members of the Kelly gang were captured through the efforts of one or more persons who acted on the offer of a reward. The plaintiffs' statement of claim in the action is not a professionally drawn document, but it is far from being as deficient as some instances of that kind. Paragraph 1 alleges that Noble and Owens were members of a detachment of Queensland Native Mounted Police, "who were contracted by the Victorian Government", with the approval of the Queensland Government, in 1879 to travel to Victoria to take part in tracking and capturing the Ned Kelly gang. A second paragraph, also numbered 1, alleges that the terms of the agreement were that the troopers were [asked] to volunteer, and that all would receive a fair share of the reward money. There is material in the appeal record that is readily capable of supporting a conclusion to that effect. Ordinarily, no doubt, it might be difficult for a police officer to establish a right to receive a reward for doing no more than his or her duty. Performing a service that one is already under a legal duty to carry out is, at common law, not generally sufficient to constitute valuable consideration for a promise to pay, or to pay more, for that service. But it would be surprising if the law required members of the Queensland police force in 1879 to serve, or to risk their lives in serving, in the pursuit of law-breakers in Victoria, which is no doubt why they were asked to volunteer for the work. In that respect, the case is somewhat analogous to that of the off-duty policeman considered in Byrne v Hoare [1965] Qd R 135.