A senior Kolkata Police officer said the tunnel, which lies on the eastern side of the road between Calcutta University ground and BNR Sports Club in the heart of the city, was a handiwork of drug addicts trying to steal copper wire and steel plates meant for electrical connections for power circuits.
No one was arrested in this connection.
Senior officers of the force rushed to inspect the tunnel off the road, which is a high security zone as it passes through Fort William, headquarters of the Army's eastern command.