law: Indian Contract Act, 1872 
  4 [16."Undue influence" defined
  (1) A contract is said to be induced by "undue
  
  influence" where the relations subsisting between the parties are such
  
  that one of the parties is in a position to dominate the will of the other and
  
  uses that position to obtain an unfair advantage over the other.
  (2) In particular and without prejudice to the generality of the
  
  foregoing principle, a person is deemed to be in a position to dominate the
  
  will of another-
  (a) where he holds a real or apparent
  
  authority over the other, or where he stands in a fiduciary relation to the
  
  other; or
  (b) where he makes a contract with a person
  
  whose mental capacity is temporarily or permanently affected by reason of age,
  
  illness, or mental or bodily distress.
  (3) Where a person who is in a position to dominate the will of
  
  another, enters into a contract with him, and the transaction appears, on the
  
  face of it or on the evidence adduced, to be unconscionable, the burden of
  
  proving that such contract was not induced by undue influence shall lie upon
  
  the person in a position to dominate the will of the other.
  Nothing in this sub-section shall affect the provisions of
  
  section 111 of the Indian Evidence Act, 1872 (1 of 1872).
   Illustrations 
  (a) A having advanced money to his son, B, during his minority,
  
  upon B's coming of age obtains, by misuse of parental influence a bond from B
  
  for a greater amount then the sum due in respect of the advance. A employs
  
  undue influence.
  (b) A, a man enfeebled by disease of age, is induced by B's
  
  influence over him as his medical attendant, to agree to pay B an unreasonable
  
  sum for his professional services, B employs undue influence.
  (c) A, being in debt to B, the money-lender of his village,
  
  contracts a fresh loan on terms which appear to be unconscionable, It lies on B
  
  to prove that the contract was not induced by undue influence.
  (d) A applies to a banker for a loan at a time when there is
  
  stringency in the money market, The banker declines to make the loan except at
  
  an unusually high rate of interest. A accepts the loan on these terms. This is
  
  a transaction in the ordinary course of business, and the contract is not
  
  induced by undue influence.]