PART III
GENERAL PROVISIONS RELATING TO REQUESTS FOR ASSISTANCE
28. Requests for assistance -
A request for assistance is a request made by the ICC to the Minister, in respect of an investigation or prosecution that the Prosecutor is conducting or proposing to conduct, in relation to a crime within the jurisdiction of the ICC, for:
(a) assistance in respect of any one or more of the following, namely –
(vi) facilitating the voluntary appearance of persons (other than prisoners) as witnesses or experts before the ICC;
Facilitating voluntary appearance of persons - authority - ICC proceedings
EDIT.