Section 209(5)(a) in The Orissa Building and Others Construction Workers (Regulation of Employment and Conditions of Service) Rules, 2002
(a)the Central Government is of the opinion that the matter of the enquiry or any part of it are of such nature that it would be against the interests of national security to hold the enquiry in public and directs the said authority or the enquiry officer, as the case may be, to hold the enquiry in camera; or