A police officer charged with a criminal offence shall, unless the Deputy Inspector-General of Police or the Assistant Inspector-General, Government Railway Police for special reasons to be recorded in writing otherwise directs, be placed under suspension from the date on which he is sent for trial, if such action has not already been taken under the provisions of rule 16.17. Suspension is compulsory during any period in which a police officer is committed to prison. A police officer, who may be arrested by order of a civil court in execution of a decree or otherwise shall be considered as under suspension from the date of arrest till his release from custody is ordered by the Court.