Part I
General
CHAPTER I
Subject-matter, scope and general principles of international judicial co-operation in criminal matters
Article 18
Optional refusal of international co-operation
1. International co-operation may be refused if the facts that substantiate the request are the subject of criminal proceedings, or if they should or may be the subject of criminal proceedings for which a Portuguese judicial authority has jurisdiction.
Complementarity
Admissibility challenge - State investigation or prosecution
EDIT.