law: Patents Act, 1970
  13. Search for anticipation by previous publication and by
  
  prior claim
  (1) The examiner to whom an application for a patent is referred
  
  under section 12 shall make investigation for the purpose of ascertaining
  
  whether the invention so far as claimed in any claim of the complete
  
  specification-
  (a) has been anticipated by publication before
  
  the date of filing of the applicant's complete specification 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) is claimed in any claim of any other
  
  complete specification published on or after the date of filing of the
  
  applicant's complete specification, being a specification filed in pursuance of
  
  an application for a patent made in India and dated before or claiming the
  
  priority date earlier than that date.
  (2) The examiner shall, in addition, make an investigation as
  
  the Controller may direct for the purpose of ascertaining, whether the
  
  invention, so far as claimed in any claim of the complete specification, has
  
  been anticipated by publication in India or elsewhere in any document other
  
  than those mentioned in sub-section (1) before the date of filing of the
  
  applicant's complete specification.
  (3) Where a complete specification is amended under the
  
  provisions of this Act before it has been accepted, the amended specification
  
  shall be examined and investigated in like manner as the original
  
  specification.
  (4) The examination and investigations required under section 12
  
  and this section shall not be deemed in any way to warrant the validity of any
  
  patent, and no liability shall be incurred by the Central Government or any
  
  officer thereof by reason of, or in connection with, any such examination or
  
  investigation or any report or other proceedings consequent thereon.