the invention, so far as claimed in any claim of the complete specification, was obtained from the opponent in the manner set out in clause (a) of sub-section (2) of section 25 and revokes the patent on that ground, he may, on request by such opponent made in the prescribed manner, direct that the patent shall stand amended in the name of the opponent;

a part of an invention described in the complete specification was so obtained from the opponent, he may pass an order requiring that the specification be amended by the exclusion of that part of the invention.

(2)

Where an opponent has, before the date of the order of the Controller requiring the amendment of a complete specification referred to in clause (b) of sub-section (1), filed an application for a patent for an invention which includes the whole or a part of the invention held to have been obtained from him and such application is pending, the Controller may treat such application and specification in so far as they relate to the invention held to have been obtained from him, as having been filed, for the purposes of this Act relating to the priority dates of claims of the complete specification, on the date on which the corresponding document was or was deemed to have been filed by the patentee in the earlier application but for all other purposes the application of the opponent shall be proceeded with as an application for a patent under this Act.