Patents Act, 1970
27. Refusal of patent without opposition
If at any time after the acceptance of the complete specification filed in pursuance of an application for a patent and before the grant of a patent thereon it comes to the notice of the Controller otherwise than in consequence of proceedings in opposition to the grant under section 25, that the invention, so far as claimed in any claim of the complete specification, has been published before the priority date of the claim-
(a) in any specification filed in pursuance of an application for a patent made in India and dated on or after the 1st day of January, 1912;
(b) in any other document in India or elsewhere, the Controller may refuse to grant the patent unless, within such time as may be prescribed, the complete specification is amended to his satisfaction:
PROVIDED that the Controller shall not refuse to grant the patent on the ground specified in clause (b) if such publication does not constitute an anticipation of the invention by virtue of sub-section (2) or sub-section (3) of section 29.