The Calcutta High Court, in Siga Technologies Inc. vs The Controller General of Patents, Designs and Trade Marks & Ors. [IPDAID/45/2024; decision dated July 24, 2026], set aside an order refusing patent application number 3206/KOLNP/2012, entitled “Polymorphic Forms of ST 246 and Methods of Preparation”, on the ground that the Controller had relied upon a document that was introduced for the first time in the post hearing written submissions filed by the pre-grant opponent therein.

The Controller refused the patent application, accepting the grounds raised in the pre-grant opposition viz lack of novelty and non-patentability under Sections 3(d) and 3(e) of the Patents Act, 1970.

The Court examined the record and found that the complete text of the said document was neither part of the record nor cited in the First Examination Report or the opposition. The Court also noted that the Respondents fairly conceded that no opportunity had been given to the Appellant to address the document.

Accordingly, the Court held that the Appellant had been denied an opportunity to deal with material that was subsequently relied upon in deciding the application. The impugned order was therefore held to have been passed in violation of the principles of natural justice and was set aside. The matter was remanded to the Controller for a fresh hearing.