Those arrested so far have been identified as Nizam (37), Ehsaan (45), Gyasuddin (38) and Naeem (35).
While the first three were employees in the business enterprise which was robbed, Naeem was a frequent visitor there and had allegedly hatched the conspiracy, said Joint Commissioner of Police (Crime) Ravindra Yadav.
The three employees were in dire need of money. So they allegedly agreed to pass on information to Naeem regarding all cash movement related to the business enterprise. Meanwhile, Naeem had contacted trained inter-state robbers in Bihar to execute the plan.
A case was registered immediately at Dabri police station and a special team was constituted to investigate the matter.
While the three employees were arrested on September 11, Naeem was nabbed the next day.
Further investigation is underway. The police are now trying to track the inter-state robbers who allegedly executed the act, Yadav added.