New Zealand Bill of Rights Act 1990

26 Retroactive penalties and double jeopardy
  • (1) No one shall be liable to conviction of any offence on account of any act or omission which did not constitute an offence by such person under the law of New Zealand at the time it occurred.

    (2) No one who has been finally acquitted or convicted of, or pardoned for, an offence shall be tried or punished for it again.