New Delhi, September 23: The roof of a cell on the walls of the Purana Qila collapsed due to heavy rains that lashed the city last week, according to workers at the monument. But Archaeological Survey of India (ASI) officials had a more complicated explanation: the roof had been knocked down for restoration work.

A K Sinha, Superintending Archaeologist, ASI, said he does not have any information about a roof collapse and will look into the matter. ‘‘It is important to take care of all structures near the fort’s walls as they have no foundation and need support from the cells,’’ said Sinha.

A senior official added that parts of the monument have collapsed over the years and they are being reconstructed. But he admitted there has been no restoration work at the said site — adjacent to the Qala-i-Kunha Masjid which faces the main gateway to the Purana Qila complex — because of financial constraints.