26.(1) On the occurrence of any public emergency, or in the interest of the public safety or tranquillity, the Government ¹[* * *] or any officer specially authorized in this behalf by ²[it], may, by order in writing, direct that any postal article or class or description of postal articles in course of transmission by post shall be intercepted or detained, or shall be disposed of in such manner as the authority issuing the order may direct. (2) If any doubt arises as to the existence of a public emergency, or as to whether any act done under sub-section (1) was in the interest of the public safety or tranquillity, a certificate of the Government ³[* * *] shall be conclusive proof on the point.