Constitution of India, 1949
20. Protection in respect of conviction for
offences.-
(1) No person shall be convicted of any
offence except for violation of the law in force at the time of the commission
of the act charged as an offence, nor be subjected to a penalty greater than
that which might have been inflicted under the law in force at the time of the
commission of the offence.
(2) No person shall be prosecuted and punished
for the same offence more than once.
(3) No person accused of any offence shall be
compelled to be a witness against himself.