Secret chamber in National Library

The the Archaeological Survey of India discovered a mysterious hidden room while restoring the Indian National Library in Alipore. They know the room is large, around 1000 square feet, but can't find a way in. What's inside? Theories so far include skeletons (it was common practice among the British to 'wall up' offenders in 'death chambers' - lovely) or hidden treasures (the British were known to hide treasures in so called 'blind chambers').

"We've searched every inch of the first floor area that forms the ceiling of this enclosure for a possible trap door. But found nothing. Restoration of the building will remain incomplete if we are not able to assess what lies inside this enclosure," said deputy superintending archaeologist of ASI, Tapan Bhattacharya. "We've come across an arch on one side of the enclosure that had been walled up. Naturally speculations are rife," said another archaeologist. Was it used as a punishment room by Hastings or one of the Lt Governors who succeeded him? It was common practice among the British to "wall up" offenders in "death chambers". Some sources say this enclosure has exactly the same look and feel. The British were also known to hide riches in blind chambers as this.
"It could be just about anything. Skeletons and treasure chests are the two things that top our speculations because it is not natural for a building to have such a huge enclosure that has no opening. We cannot break down a wall, considering the importance of the building. So we have decided to bore a hole through the wall to peer inside with a searchlight," said D V Sharma, regional director, ASI.

Secret chamber in National Library