law: Indian Trusts Act, 1882 
  53. Trustee may not buy beneficiary's interest without permission
  
   
  Not trustee, and no person who has recently ceased to be a
  
  trustee, may, without the permission of a principal civil court of original
  
  jurisdiction, buy or become mortgagee or lessee of the trust-property or any
  
  part thereof; and such permission shall not be given unless the proposed
  
  purchase, mortgage or lease is manifestly for the advantage of the beneficiary.
  
  
  Trustee for purchase
  And no trustee whose duty it is to buy or to obtain a mortgage
  
  or lease of particular property for the beneficiary may buy it, or any part
  
  thereof, or obtain a mortgage or lease of it, or any part thereof, for himself.