Related Rule
Germany
Practice Relating to Rule 161. International Cooperation in Criminal Proceedings
Section C. Extradition of own nationals
Germany’s Law on International Legal Assistance in Criminal Matters (1982) states:
§ 2 Principle
(1) A foreign person who, in a foreign State, is prosecuted or has been convicted for an offence punishable in that State, can, on the request of a competent authority, be extradited to that State …
(3) Foreign persons in the terms of this law are persons who are not German nationals in the meaning of Article 116 paragraph 3 of the Basic Law [of the Federal Republic of Germany]. 
Germany, Law on International Legal Assistance in Criminal Matters, 1982, § 2(1) and (3).
Germany’s Law on International Legal Assistance in Criminal Matters (1982), as amended in 2006, states:
Part One – Scope of Application
§ 1 Scope of application
(1) Legal assistance in criminal matters with foreign countries is based on this law.
(3) Provisions of international agreements, insofar as they have become directly applicable domestic law, have priority over the provisions of this law.
(4) Assistance for proceedings in criminal law matters with a Member State of the European Union is based on this law. Paragraph 3 is applied with the proviso that Part Eight of this law has priority over the international agreements mentioned there. The international agreements mentioned in paragraph 3 and the provisions on legal assistance without treaty of this law remain applicable in a subsidiary manner, insofar as Part Eight does not contain final provisions.
Part Eight – Assistance to Member States of the European Union
§ 80 Extradition of German nationals
(1) Extradition of a German national for the purpose of prosecution is permissible only, if
1. it is ensured that, after pronouncement of a final custodial sentence or another sanction, the Member State seeking extradition will, at the request of the wanted person, offer to transfer that person back into the area of application of this law for the enforcement of the sentence, and
2. the offence has a significant link to the Member State seeking extradition.
(2) If the conditions of paragraph 1, sentence 1, No. 2 are not fulfilled, extradition of a German national for the purpose of prosecution is permissible only if
1. the conditions of paragraph 1, sentence 1, No. 1 are fulfilled, and the offence
2. has no significant link to [Germany], and
3. the offence is unlawful also according to German law …, and if, in a concrete weighting of the conflicting interests, the legitimate expectation of the wanted person not to be extradited does not prevail.
(3) Extradition of a German national for the purpose of enforcement of a sentence is permissible only if the wanted person, after information and recorded by a judge, consents to it. 
Germany, Law on International Legal Assistance in Criminal Matters, 1982, as amended in 2006, Sections 1(1) and (3)–(4 ) and 80(1)–(3).