Section 666(b) in Police Regulations, Bengal , 1943
(b)Permanent police guards supplied to banks, to railways other than State Railways and to other non-Government concerns shall be considered as part of the regular establishment employed on normal duties and not as additional police appointed under section 13 or 14 of the Police Act, 1861 to keep the peace. Credits for the cost of these guards will be treated as provincial receipts, recoveries being made by the Accountant-General.