(b)as might involve the disclosure of proceedings of the Council of Ministers or of any Committee thereof and for the purpose of this sub-section, a certificate issued by a Secretary to the Government certifying that any information, answer or portion of a document, is of the nature specified in clause (a) or clause (b) shall be binding and conclusive; provided that the Lokpal may require any information or answer or portion of document in respect of which a certificate is issued under this sub-section to the effect that it is of the nature as specified in clause (b) to be disclosed to him in private for scrutiny and if on such scrutiny the Lokpal is satisfied that such certificate ought not to have been issued, he shall declare the certificate to be of no effect.