EU Directive 2014/41/EU, with the European Investigation Order (EIO).
For countries who have not implemented this EU Directive:
- European Convention on Mutual Assistance in Criminal Matters, Strasbourg, 20/04/1959
- Additional Protocol to the European Convention on Mutual Assistance in Criminal Matters, Strasbourg, 17/03/1978
- EU Convention on Mutual Legal Assistance in Criminal Matters, Brussels, 29/05/2000
- The Schengen Agreement (Schengen, 19 juni 1990).