The CB-CID has taken over the investigations of the train robbery and has started by questioning the railway and bank employees. No solid leads have been found yet.

With the investigating authorities strongly suspecting that the robbery was an insider job, bank and railway employees, porters and parcel officers are under scrutiny. Blood samples and fingerprints collected from the spot were sent for testing, to see if they match any of the employees. CCTV footage were retrieved from various spots and are being examined. Also under surveillance are those who deal with soiled notes.

Nearly Rs. 5.75 crores of soiled and damaged notes, belonging to the RBI, were stolen from the Salem-Chennai Egmore Express train on August 9. The robbers had gained entry into the parcel coach through the chiselled roof of the compartment. The parcel coaches were transporting Rs 325 crore in 226 sealed wooden boxes.

It may be noted that the Salem Junction-Chennai Egmore train was used as a carriage six times in the past for transporting cash.