Part VI
Mutual legal assistance in criminal matters
CHAPTER III
Special forms of international assistance
Article 157
Safe conduct
1. Any person appearing on the territory of a foreign State under the terms and for the purposes of the provisions of Articles 154, 155 or 156 above :
a) shall not be arrested, prosecuted, punished or subjected to any other restriction of his personal liberty in respect of any act anterior to his departure from the Portuguese territory other than those mentioned in the request for co-operation ;
b) shall not be under an obligation to accept to be heard or make a statement at proceedings other than those mentioned in the request.
2. The immunity provided for in paragraph 1 above shall cease when the person voluntarily remains in the territory of the foreign State for more than 45 days from the date when his presence is no longer required or, having left that territory, voluntarily returned to it.
3. The provisions of the preceding paragraphs shall apply mutatis mutandis to any person habitually resident in a foreign State who comes to Portugal as a result of a summons to appear for purposes of criminal proceedings.
Person sought for different crime
Facilitating voluntary appearance of persons - authority - ICC proceedings
Temporary transfer of persons in custody for purposes of identification or for obtaining testimony or other forms of assistance - authority - ICC proceedings
Assurance that the witness will not be prosecuted, detained or subjected to restriction of personal freedom
EDIT.