The courts have given another judgment, Ahmed v Crown Prosecution Service [2017] EWHC 1272 (Admin), which helps the police in considering what actions fall within the execution of their duty. In short, where a police officer genuinely and reasonably believes that they are authorised by a court order to arrest a person for breach of an injunction and that the person is in breach of it, they will be acting in the course of their duty if they arrest that person. Even where there is no valid injunction. Sort of. The case is not available on Bailii – possibly because it was given ex tempore. It is on Lawtel and Westlaw.