Van Esbroeck

The ne bis in idem principle, enshrined in Article 54 of the Convention implementing the Schengen Agreement (…), must be applied to criminal proceedings brought in a Contracting State for acts for which a person has already been convicted in another Contracting State even though the Convention was not yet in force in the latter State at the time at which that person was convicted, in so far as the Convention was in force in the Contracting States in question at the time of the assessment, by the court before which the second proceedings were brought, of the conditions of applicability of the ne bis in idem principle.

Article 54 of the Convention must be interpreted as meaning that :

- the relevant criterion for the purposes of the application of that article is identity of the material acts, understood as the existence of a set of facts which are inextricably linked together, irrespective of the legal classification given to them or the legal interest protected;

- punishable acts consisting of exporting and importing the same narcotic drugs and which are prosecuted in different Contracting States to the Convention are, in principle, to be regarded as ‘the same acts’ for the purposes of Article 54, the definitive assessment in that respect being the task of the competent national courts.