20. In that regard, it must be borne in mind that, according to the Court’s settled case-law, if the judicial review guaranteed by Article 47 of the Charter is to be effective, on the one hand, the person concerned must be able to ascertain the reasons upon which the decision taken in relation to him is based, either by reading the decision itself or by requesting and obtaining notification of those reasons, so as to make it possible for him to defend his rights in the best possible conditions and to decide, with full knowledge of the relevant facts, whether there is any point in his applying to the court with jurisdiction. On the other, the court with jurisdiction must have the power to require the authority concerned to provide that information, in order to put that court fully in a position in which it may carry out the review of the lawfulness of the national decision in question (see to that effect, judgment in ZZ, EU:C:2013:363, paragraph 53 and the case-law cited).
21. It is also clear from the Court’s case-law that, as regards judicial proceedings, having regard to the adversarial principle that forms part of the rights of the defence which are referred to in Article 47 of the Charter, the parties to a case must have the right to examine all the documents or observations submitted to the court for the purpose of influencing its decision, and to comment on them. The fundamental right to an effective legal remedy would be infringed if a judicial decision were founded on facts and documents which the parties themselves, or one of them, have not had an opportunity to examine and on which they have therefore been unable to state their views (judgment in ZZ, EU:C:2013:363, paragraphs 55 and 56 and the case-law cited).
22. However, it does not appear that, in a case such as that at issue in the main proceedings, the principles referred to in paragraphs 20 and 21 of the present judgment have been infringed. It follows from the order for reference that Unitrading knew of the grounds on which the decision concerning it is based, that it was aware of all the documents and observations submitted to the court with a view to influence its decision and that it was able to comment on them before that court.
23. In those circumstances, the results of the examinations provided by the American laboratory merely constitute evidence which both the customs authorities and the Netherlands courts, also taking account of the arguments and evidence submitted by Unitrading, were able to regard as adequate to establish the true origin of the goods. As the Commission has rightly pointed out, given that there is no legislation at EU level governing the concept of proof, any type of evidence admissible under the procedural law of the Member States in proceedings similar to those laid down in Article 243 of the Customs Code is in principle admissible (judgment in Sony Supply Chain Solutions (Europe), C‑153/10, EU:C:2011:224, paragraph 41 and the case‑law cited).
24. The admissibility of such evidence, even if it is important or decisive for the outcome of the dispute concerned, cannot be called into question by the sole fact that that evidence cannot fully be verified by either the party concerned or the court hearing the matter, as appears to be the case of the results of the examinations by the American laboratory in the main proceedings. Although, in such a case, the party concerned cannot fully verify the accuracy of those results of the examinations, it is not, however, in a situation comparable to that at issue in the case which gave rise to the judgment in ZZ (EU:C:2013:363), where both the national authority concerned and the court hearing an action against the decision adopted by that authority refused, by application of the national legislation at issue in that case, to give precise and full disclosure to the person concerned of the grounds on which the decision concerning him was based.
25. Nor does it appear that the right to effective judicial protection has been infringed in the dispute in the main proceedings, given that the courts seised in turn do not appear to be bound, under the national procedural law, by the assessment of the facts made and, in particular, the type of evidence used by the customs authority (see, to that effect, judgment in Wilson, C‑506/04, EU:C:2006:587, paragraph 61).
26. Since the relevance of evidence not entirely verifiable by all the parties to the proceedings or by the court hearing the case, as is the situation as regards the results of the examinations at issue in the main proceedings, can validly be challenged by the party concerned, in particular by arguing that that evidence can constitute only indirect proof of the facts alleged and by putting forward other evidence to support his assertions, the right of that person to effective judicial protection, referred to in Article 47 of the Charter, has not, in principle, been infringed. As is apparent from the order for reference and the observations of the Netherlands Government submitted at the hearing, the courts seised in turn in the main proceedings appear to be free to assess the relevance of the evidence submitted to them.
27. Since Article 245 of the Customs Code provides, in that context, that the provisions for the implementation of the appeals procedure provided for in Article 243 of that code are to be determined by the Member States, it must be held that it is for the domestic legal system of each Member State to lay down the detailed procedural rules governing those actions, provided that such rules are not less favourable than those governing similar domestic actions (principle of equivalence) and that they do not render in practice impossible or excessively difficult the exercise of rights conferred by Community law (principle of effectiveness). Those considerations also apply with regard, specifically, to evidential rules (see, to that effect, judgment in Direct Parcel Distribution Belgium, C‑264/08, EU:C:2010:43, paragraphs 33 and 34 and the case-law cited).
28. In order to ensure compliance with the principle of effectiveness, if the national court finds that the fact of requiring the person liable for the customs debt to prove the place of origin of the goods declared, in that the onus is on him to refute the relevance of indirect evidence used by the customs authorities, is likely to make it impossible or excessively difficult for such evidence to be produced, since inter alia that evidence relates to data which the person liable could not possess, it is required to use all procedures available to it under national law, including that of ordering the necessary measures of inquiry (see, to that effect, judgment in Direct Parcel Distribution Belgium, EU:C:2010:43, paragraph 35 and the case-law cited).
29. Nevertheless, where the national court, after having used all procedures available to it under national law, concludes that the true origin of the goods concerned is different from that declared and that the imposition on the declarant of additional customs duties, or even a fine, is therefore justified, Article 47 of the Charter does not preclude a decision to that effect being adopted by that court.
30. Having regard to the foregoing considerations, the answer to the first question is that Article 47 of the Charter must be interpreted as not precluding proof of origin of imported goods adduced by the customs authorities on the basis of national procedural rules resting on the results of an examination carried out by a third party, with regard to which that third party refuses to disclose further information either to the customs authorities or to the customs declarant, as a result of which it is made difficult or impossible to verify or disprove the correctness of the conclusions reached, provided that the principles of effectiveness and equivalence are upheld. It is for the national court to ascertain whether that is so in the main proceedings.
The second and third questions
31. By its second and third questions, which it is appropriate to examine together, the referring court asks, in essence, whether, in a situation such as that at issue in the main proceedings, and when the customs authorities cannot disclose further information in respect of the examination carried out, Article 47 of the Charter must be interpreted as meaning that the rights which it enshrines mean that the customs authorities must grant the request of the party concerned that it conduct, at its own expense, an examination in the country declared as the country of origin. In addition, the referring court asks whether it matters that portions of the samples of the goods, to which the party concerned could have obtained access with a view to having an examination carried out by another laboratory, were still available for a limited period and, if so, whether the customs authorities must inform the party concerned that portions of the samples of the goods are still available and that it may request those samples for purposes of such an examination.
32. In order to answer the second and third questions, it must be borne in mind, firstly, that Article 47 of the Charter does not preclude, in principle, the proof of origin of imported goods, adduced by the customs authorities on the basis of national procedural law, resting on the results of examinations carried out by a third party of which it is impossible to verify or refute the accuracy, provided that the principles of effectiveness and equivalence are upheld.