Editing Polyukhovich v Commonwealth (section)

==Background==
The [http://www.austlii.edu.au/au/legis/cth/consol_act/wca1945121/ ''War Crimes Act 1945'' (Cth)] provided that any person who committed a war crime between 1 September 1939 and 8 May 1945 was guilty of an [[indictable offence]]. [[Ivan Polyukhovich|Ivan Timofeyevich Polyukhovich]] had been charged under the Act with war crimes, alleged to have been committed between September 1942 and May 1943 in [[Ukraine]] while it was under German occupation in [[World War II]].

Polyukhovich's lawyers argued that the law was beyond the scope of Commonwealth legislative power in section 51(vi) (defence) and section 51(xxix) (external affairs) of the Constitution. He further argued that the attempt to make past criminal conduct an offence was an invalid attempt to usurp the judicial power of the Commonwealth, that power being vested by the Constitution in Chapter III courts, by enacting what was effectively a [[bill of attainder]].{{citation needed|date=August 2016}}