‘(1) Information … is exempt information if its disclosure would, or would be likely to, prejudice— (a) the prevention or detection of crime, (b) the apprehension or prosecution of offenders (c) ….. (g) the exercise by any public authority of its functions for any of the purposes specified in subsection (2)… (2) The purposes referred to in subsection (1)(g) to (i) are— (a) the purpose of ascertaining whether any person has failed to comply with the law, (b) the purpose of ascertaining whether any person is responsible for any conduct which is improper, (c) the purpose of ascertaining whether circumstances which would justify regulatory action in pursuance of any enactment exist or may arise…’