Thiruvananthapuram: Kerala police have taken into custody three men at the end of a swift investigative operation in connection with the theft of Rs3.5 million (Dh187,463) from a government engineering college in Thrissur.

The three were identified as Thattil Rijo, 30, and his brothers Lijo and Sijo who are twins aged 33. Police recovered Rs3 million from the trio.

Rijo worked in the college office, and had known that there would be a large amount of money in the college at this time of the year, which is admission time.

The heist occurred on Saturday, and police only had visuals from a camera in the college principal’s room to work with. The visual showed a man in black wearing a helmet, with a red backpack.

Police believe that Rijo had managed to make a duplicate key of the locker in which the money was stored, and chose a weekend when there were no classes to carry out the heist.

Police suspected an insider to have played a role in the theft because neither the lock on the principal’s door nor the lock on the cash box was broken. In the visual, the intruder was seen walking into the principal’s room and walking out within minutes, indicating that the person knew his way around the room.

Police then questioned several people, screened mobile calls and examined visuals from other cameras in the vicinity before they got to the accused.

The brothers have reportedly confessed that financial constraints at home had made them chalk out the plan to steal money from the college. The twin brothers had been running a business of selling bags, which was not doing well in recent times, and the family was in severe debt.