Related Rule
Portugal
Practice Relating to Rule 161. International Cooperation in Criminal Proceedings
Section B. Extradition
Portugal’s Law on International Judicial Cooperation in Criminal Matters (1999), as amended in 2001, provides:
1. Extradition may be granted only for the purpose either of instituting criminal proceedings or of executing a sanction or measure involving deprivation of liberty, for an offence that the courts of the requesting State have jurisdiction to try.
2. For any such purpose, surrender of a person shall be possible only in respect of offences, including attempted offences, that are punishable under both the Portuguese law and the law of the requesting State by a sanction or measure involving deprivation of liberty for a maximum period of at least one year … 
Portugal, Law on International Judicial Cooperation in Criminal Matters, 1999, as amended in 2001, Article 31.
Trial of an extradited person sentenced by Gacaca Courts
A person extradited to be tried in Rwanda and who has been sentenced by Gacaca Courts shall be tried by a competent court as provided by this Organic Law.
However, the decision of the Gacaca Court shall first be nullified by that court. 
Rwanda, Organic Law terminating Gacaca Courts and determining mechanisms for solving issues which were under their jurisdiction, 2012, Article 8.