s 115A Provost Marshal's duty in relation to independence of investigations
(1) Subsection (2) applies in relation to each service police force. (2) The Provost Marshal of the force has a duty, owed to the Defence Council, to seek to ensure that all investigations carried out by the force are free from improper interference. (2A) The Provost Marshal for serious crime has a duty, owed to the Defence Council, to seek to ensure that all investigations carried out by the tri-service serious crime unit are free from improper interference. (3) “ Improper interference ” includes, in particular, any attempt by a person who is not a service policeman to direct an investigation which is being carried out by the force or (as the case may be) the unit.