Section 329(f) in Police Regulations, Bengal , 1943
(f)Prisoners shall be taken out to relieve nature at as late an hour as possible before officers retire to rest, in order that it may not be necessary to open the lock-up again during the night. Before being taken out they shall be secured with leg-shackles, handcuffs or rope. They shall not be allowed out of sight: and when relieving nature shall be attached by means of a rope to a constable.
