The absence of a police caution before an interview does not vitiate an otherwise lawful arrest; it is relevant only to the admissibility of any statement obtained. The tort of wrongful arrest cannot be established merely by showing the arrest was 'inappropriate' or 'unreasonable' — there is no support in the authorities for such a vague test. The question whether abuse of the power of arrest can render an otherwise lawful arrest tortious was left open.
The full text is available to signed-in members, including the 2 later cases that cite this judgment.