law: Patents Act, 1970
  19. Powers of Controller in case of potential infringement
  (1) If, in consequence of the investigation required by the
  
  foregoing provisions of this Act or of proceedings under section 25, it appears
  
  to the Controller that an invention in respect of which an application for a
  
  patent has been made cannot be performed without substantial risk of infringement
  
  of a claim of any other patent, he may direct that a reference to that other
  
  patent shall be inserted in the applicant's complete specification by way of
  
  notice to the public, unless within such time as may be prescribed-
  (a) the applicant shows to the satisfaction of
  
  the Controller that there are reasonable grounds for contesting the validity of
  
  the said claim of the other patent; or
  (b) the complete specification is amended to
  
  the satisfaction of the Controller.
  (2) Where, after a reference to another patent has been inserted
  
  in a complete specification in pursuance of a direction under sub-section (1)-
  (a) that other patent is revoked or otherwise
  
  ceases to be in force; or
  (b) the specification of that other patent is
  
  amended by the deletion of the relevant claim; or
  (c) it is found, in proceedings before the
  
  court of the Controller, that the relevant claim of that other patent is
  
  invalid or is not infringed by any working of the applicant's invention.
  the Controller may, on the application of the applicant, delete
  
  the reference to that other patent.