Hemant Nagrale, Navi Mumbai commissioner of police said in a statement, "There is a case of house-breaking theft in Bank of Baroda, Juinagar branch".
The police said the tunnel led to a shop near the bank.
Thirty lockers in the Juinagar branch of Bank of Baroda were broken into over the weekend by burglars who dug a tunnel to the bank from a neighbouring shop.
The theft came to light on Monday when the bank staff went to the locker room and found it in complete disarray, with numerous lockers still open.
Over time, they dug a 25-feet long tunnel to reach the branch's locker room. Of 237 lockers, 30 lockers were found open. This shop housing private lockers rented out to people for safe keeping of valuable and documents.
Tushar Doshi, deputy commissioner of police (crime), said, "It is impossible to dig a tunnel that ends exactly under the locker room without having an idea about the bank's structure".
The bank has 225 lockers, and the robbers broke into 30 of them, PTI quoted a senior police officer as saying. "We have got clues about the accused and our teams are working on them", Assistant police inspector (Turbhe division) Mr. Kiran Patil said.
The bank, incidentally, had not installed CCTV cameras in the locker room to protect the customer's privacy. The incident came to light when a customer and a bank officer entered found that 27 lockers had been broken into. The bank had called all its customers and was verifying other records.
It was reported that the robbers allegedly robbed valuables worth over Rs 40 lakh.
A case has been registered with the Sanpada police under Sections 454 (house break), 457 (house break at night) and 380 (theft in dwelling house) of the Indian Penal Code.