Part 4 Mutual Assistance through the Execution of Decisions and Orders of the Court
§ 42 Escape and Speciality
(relating to Article 108, Article 111 of the Rome Statute)
(2) Prosecution for criminal acts that the convicted person committed prior to his surrender to the German authorities or the execution of a prison sentence imposed prior to surrender or measures for the prevention of crime and the reformation of offenders (Maßregel der Besserung und Sicherung) shall occur subject to the provisions of Article 108 para. 3 of the Rome Statute only upon agreement of the Court.
(3) If a foreign state requests extradition, provisional extradition, deportation, or other transfer to its sovereign territory for criminal prosecution or execution of a sentence or other sanction, approval may be given when the Court, subject to the provisions of Article 108 para. 3 of the Rome Statute, has given prior approval and the extradition is permissible according to the extradition regulations applicable to the requesting state.
Limitation on the prosecution or punishment of other offences
EDIT.