law: Court Fees Act, 1850 
  17.Effect of fraud or mistake .- 
  (1) Where, in the case of any suit or application for which a
  
  period of limitation is prescribed by this Act,--
  (a) the suit or application is based upon the
  
  fraud of the defendant or respondent or his agent; or
  (b) the knowledge of the right or title on
  
  which a suit or application is founded is concealed by the fraud of any such
  
  person as aforesaid; or
  (c) the suit or application is for relief from
  
  the consequences of a mistake; or
  (d) where any document necessary to establish
  
  the right of the plaintiff or applicant has been fraudulently concealed from
  
  him;
  the period of limitation shall not begin to
  
  run until the plaintiff or applicant has discovered the fraud or the mistake or
  
  could, with reasonable diligence, have discovered it; or in the case of a
  
  concealed document, until the plaintiff or the applicant first had the means of
  
  producing the concealed document or compelling its production:
  Provided  that nothing in this section shall
  
  enable any suit to be instituted or application to be made to recover or
  
  enforce any charge against, or set aside any transaction affecting, any
  
  property which—
  ( i )in the case of fraud,
  
  has been purchased for valuable consideration by a person who was not a party
  
  to the fraud and did not at the time of the purchase know, or have reason to
  
  believe, that any fraud had been committed, or
  (ii) in the case of mistake, has been
  
  purchased for valuable consideration subsequently to the transaction in which
  
  the mistake was made, by a person who did not know, or have reason to believe,
  
  that the mistake had been made, or
  (iii) in the case of a concealed document, has
  
  been purchased for valuable consideration by a person who was not a party to
  
  the concealment and, did not at the time of purchase know, or have reason to
  
  believe, that the document had been concealed.
  (2) Where a judgment-debtor has, by fraud or
  
  force, prevented the execution of a decree or order within the period of
  
  limitation, the court may, on the application of the judgment-creditor made
  
  after the expiry of the said period extend the period for execution of the
  
  decree or order:
  Provided  that such application is made within
  
  one year from the date of the discovery of the fraud or the cessation of force,
  
  as the case may be.