Chapter II Cooperation with the International Criminal Court
Section 3 Surrender of an Offender Sought for Surrender, etc.
Subsection 1 Surrender of an Offender Sought for Surrender
(Measures by the Minister of Justice)
Article 20 (1) (iv) when complying with the request for cooperation would risk obstructing the investigation or trial in a case connected with a crime other than the offense underlying the cooperation request, that is being investigated by a Japanese public prosecutor, public prosecutor's assistant officer, or judicial police official, or a case connected with a crime other than the offense underlying the cooperation request (limited to a crime committed by a person other than the offender sought for surrender), that is pending before a Japanese court, and it is found inappropriate to immediately comply with said request;
Postponement of execution of ICC request
Postponement - ongoing investigation or prosecution
EDIT.