The Central Bureau of Investigation has started probing the Adarsh Housing Society issue. “We have asked for certain information from the Society, the Navy and the Collector,” Joint Director Rishi Raj Singh told journalists here on Friday.

Mr. Singh said the CBI had sought from the Society the source of income of public servants (who are its members) and documents on environmental clearance and security norms.

The security norm is applicable to structures which come up within 200 metres of a defence installation. High-rise buildings can pose a security threat.

Senior CBI officials said only the Collector had given the entire file. “But we have not received any response from the Navy or the housing Society,” a senior official said.

The file submitted by the Collector should have details of environmental clearance and security norms. But information about the source of income of the public servants should be furnished by the Society.