26. (1) Revocation of a patent in whole or in part may be obtained on petition to or on a counter claim in a suit for infringement before the High Court Division on all or any of the following grounds, namely:- (a) that the invention has been the subject of a valid prior grant of a patent in Bangladesh; (b) that the true and first inventor or his legal representative or assign was not the applicant or one of the applicants for the patent; (c) that the patent was obtained in fraud of the rights of the person applying for the revocation or of any person under or through whom he claims; (d) that the invention was not, at the date of the patent, a manner of new manufacture or improvement; (e) that the invention does not involve any inventive step, having regard to what was known or used prior to the date of the patent; (f) that the invention is of no utility; (g) that the complete specification does not sufficiently and fairly describe and ascertain the nature of the invention and the manner in which the invention is to be performed; (h) that the complete specification does not sufficiently and clearly ascertain the scope of the invention claimed; (i) that the patent was obtained on a false suggestion or representation; (j) that the primary or intended use or exercise of the invention is contrary to law; (k) that the patentee has contravened, or has not complied with, the conditions contained in the patent; (l) that the complete specification does not disclose the best method of performance of the invention known to the applicant for the patent at the time when the specification was left at the Department of Patents, Designs and Trade Marks. (m) that prior to the date of the patent, the patentee or other persons (not being authorities administering any department of Government, or the agents or contractors of, or any other persons authorised in that behalf by the Government secretly worked the invention on a commercial scale (and not merely by way of reasonable trial or experiment) in Bangladesh, and thereby made direct or indirect profits in excess of such amount as the Court may in consideration of all the circumstances of the case deem reasonable; (n) that the invention claimed in the complete specification is not the same as that contained in the provisional specification, and that the invention claimed, so far as it is not contained in the provisional specification, was not new at the date when the complete specification was filed: Provided that this sub-section shall have effect in relation to the ground of revocation specified- (i) in clause (b), subject to the provisions of section 78A, or (ii) in clause (d), subject to the provisions of sub-section (1) of section 13, sub-section (12) of section 21A, section 38 and section 40. (2) A petition for revocation of a patent may be presented− (a) by the ¹[Attorney General] or any person authorized by him; or (b) by any person alleging- (i) that the patent was obtained in fraud of his rights, or of the rights of any person under or through whom he claims; or (ii) that he, or any person under or through whom he claims, was the true and first inventor of any invention included in the claim of the patentee; or (iii) that he, or any person under or through whom he claims an interest in any trade, business or manufacture, had publicly manufactured, used or sold, within Bangladesh, before the date of the patent, anything claimed by the patentee as his invention. (3) The High Court Division may, irrespective of any provisions of the Code of Civil Procedure, 1908, in this behalf, require any person, other than the ²[Attorney General] or any person authorised by him, applying for the revocation of a patent to give security for the payment of all costs incurred or likely to be incurred by any person appearing to oppose the petition.