The Exclusion of Evidence Obtained by Violating a Fundamental Right: Pragmatism Before Principle in the Strasbourg Jurisprudence


The Exclusion of Evidence Obtained by Violating a Fundamental Right: Pragmatism Before Principle in the Strasbourg Jurisprudence



EVIDENCE SCHOLARS HAVE long discussed the normative (and empirical) arguments relating to the admissibility of improperly obtained evidence. This chapter focuses on two aspects of this debate—the narrower issue of the admissibility of evidence obtained by the violation of a fundamental or human right, and the contribution of the European Court of Human Rights in Strasbourg on this issue. It will be argued that the Court has begun to move away from some basic doctrines of European human rights law, and that some of its recent pronouncements in criminal cases raise questions about the fundamental structure of the European Convention on Human Rights, notably in relation to the fair trial right in Article 6. Two particular aspects of the interpretation of Article 6 are questioned: first, to what extent should ‘public interest’ factors be relevant in determining whether the right to a fair trial under Article 6 has been violated? Secondly, under what circumstances, if any, should the use of evidence obtained through violation of another Convention right render a trial unfair under Article 6?

Section 1 of this chapter prepares the ground for this enquiry, by setting out the overarching structure of the ECHR. Section 2 considers the general approach to the fair trial right in Article 6 and summarises some of the ‘public interest’ arguments that were advanced in the late 1990s. Section 3 examines the way in which, in more recent cases, the Court has begun to cite the public interest in prosecutions for serious crime as a reason for taking a different approach. In Section 4 the Court’s approach to Article 3 (prohibiting torture and inhuman or degrading treatment) is set out as a basis for Section 5’s examination of the Court’s approach to the interaction between Articles 3 and 6. Finally, Section 6 turns to the question of the interaction between Article 8 (right to respect for private life) and Article 6, and exposes weaknesses in the Court’s judgments, both in terms of their internal coherence and in relation to the normative structure of the Convention.


Although there is no official ranking of the rights set out in the ECHR, there are two reasons for concluding that the Convention does establish a hierarchy of rights. The first reason derives from Article 15 of the Convention, which singles out certain rights for special treatment:

Article 15

1. In time of war or other public emergency threatening the life of the nation any High Contracting Party may take measures derogating from its obligations under this Convention to the extent strictly required by the exigencies of the situation, provided that such measures are not inconsistent with its other obligations under international law.

2. No derogation from Article 2, except in relation to deaths resulting from lawful acts of war, or from Article 3, 4 (paragraph 1) and 7 shall be made under this provision.

The thrust of Article 15 is that it is permissible for states to derogate from various Convention rights if the conditions for doing so are satisfied, but that no derogation at all is allowed from four rights:

— the right to life (Article 2);

— the right not to be subjected to torture or inhuman or degrading treatment (Article 3);

— the right not to be subjected to forced labour (Article 4.1); and

— the right not to be subjected to retrospective criminal laws or penalties (Article 7).1

The fact that these provisions are singled out as non-derogable may be taken to indicate that they are the most basic of the fundamental rights in the Convention. Of course, their meaning and reach are subject to interpretation, and in that sense they are not absolute rights2—at least, not until the scope of their application has been finally determined. It could be argued, per contra, that rights placed in the non-derogable category are not more fundamental than other rights, but are simply open to fewer weighty countervailing interests than other Convention rights. But, even if that were so, the effect of Article 15 is to place these rights in a specially protected category and, it is submitted, to indicate the beginnings of a hierarchy.

The second reason for discerning a hierarchy of rights in the Convention is the differing degree to which the Convention admits qualifications upon its rights. This is most evident in those Convention rights which might be termed qualified or prima facie rights—the right is declared, but with the rider that it may be interfered with on certain grounds, to the minimum extent possible. Such qualifications circumscribe the right to respect for private life (Article 8), the right to freedom of thought and religion (Article 9), the right to freedom of expression (Article 10), and the right to freedom of assembly and association (Article 11). All these qualified rights appear in the Convention with a second paragraph, which states that each right may be subject to interference if it can be established that this is ‘necessary in a democratic society’ on one of the stated grounds. The jurisprudence of the Strasbourg Court interprets the second paragraphs of these Articles in such a way as to impose meaningful limitations on state interference with the rights, chiefly through the doctrine of proportionality. This is a major point of differentiation between these qualified rights and the non-derogable rights mentioned earlier, since the latter leave no room for the operation of the proportionality doctrine.

Situated between non-derogable rights and qualified rights is an intermediate category, which is less easy to label and more difficult to assess. In the European Convention this category includes the right to liberty and security of the person (Article 5) and the right to a fair trial (Article 6). One might refer to the rights in this intermediate category as ‘strong rights’, to demonstrate that their strength is not qualified in the way that the rights in Articles 8–11 are qualified. Indeed, the rights in Articles 5 and 6 are not subject to any explicit qualification on the face of the Convention text. In the internal logic of the ECHR, this is a significant distinction. What it suggests is that, although strong rights are less fundamental than the non-derogable rights, any rationale for curtailing a strong right must, at a minimum, be more powerful than the kind of ‘necessary in a democratic society’ argument that is needed to establish the acceptability of interference with one of the qualified rights. Identifying the features and evaluating the cogency of arguments for curtailing the fair trial right in Article 6 are amongst this chapter’s central objectives.

The analysis thus far points up a significant difference between the European Convention and some other statements of basic rights such as the Canadian Charter of Rights and Freedoms, section 1 of which states that the rights and freedoms are guaranteed ‘subject only to such reasonable limits prescribed by law as can be demonstrably justified in a free and democratic society’. The presence of section 1 has engendered a nuanced Supreme Court jurisprudence on when and for what precise reasons various rights can be curtailed.3 The important difference in the structure of the European Convention is that the equivalent of the ‘free and democratic society’ exception is found only in qualified rights such as those declared by Articles 8–11, and does not apply to all rights. Occasionally the Strasbourg Court has expressed itself as if the Canadian position also obtained under the ECHR. Consider, for example, the Strasbourg Court’s much-cited statement in Sporrong and Lönnroth v Sweden:4

[T]he Court must determine whether a fair balance was struck between the demands of the general interest of the community and the requirements of the protection of the individual’s fundamental rights. The search for this balance is inherent in the whole of the Convention and is also reflected in the structure of Article 1.5

The first part of the final sentence is an exaggeration. It cannot seriously be suggested that when determining whether there has been a breach of Article 2 (right to life) or Article 3 (no torture etc) it is relevant to weigh the public interest against the individual’s right. That kind of balancing has never formed part of Article 2 decisions, and we will see later in the chapter that it would be most unusual in relation to Article 3. The first part of the final sentence was clearly not intended as an authoritative pronouncement on the proper approach to all questions under the Convention, despite its unguarded terms. More accurate is the second part of the final sentence, which brings the issue specifically to the matter before the Court, the correct interpretation of Article 1 of Protocol 1’s right to peaceful enjoyment of possessions. Indeed, it could be argued that the two sentences are commonly cited out of context, since the words immediately preceding the quoted passage are ‘for the purposes of the latter provision’, which is a direct reference to Article 1 of Protocol 1. It is submitted that Sporrong and Lönnroth v Sweden cannot be relied on as a basis for the argument that a court must balance the individual’s right against the general interests of the community in any case arising under the Convention.


The preceding Section addressed the structure of the Convention and its logical implications for the broad ‘public interest’ arguments on which governments often wish to rely. We must now look more closely at how the Strasbourg Court has reacted to ‘public interest’ arguments when they have been advanced as possible limitations on rights that form part of the general right to a fair trial in criminal cases, safeguarded by Article 6. Three examples of the approach taken by the Court in the late 1990s may be offered to illustrate baseline interpretational principles.

First, in Saunders v United Kingdom6 the question was whether the privilege against self-incrimination was an implied right, falling within the general right to a fair trial under Article 6. If so, did it apply in this case? And if it was in fact applicable, should it be upheld notwithstanding the pressing social importance of combating serious fraud? Having answered the first two questions in the affirmative, the Court squarely addressed the third question:

[The Court] does not accept the Government’s argument that the complexity of corporate fraud and the vital public interest in the investigation of such fraud and the punishment of those responsible could justify such a marked departure as that which occurred in the present case from one of the basic principles of a fair procedure… The general requirements of fairness contained in Article 6, including the right not to incriminate oneself, apply to criminal proceedings in respect of all types of criminal offences without distinction, from the most simple to the most complex. The public interest cannot be invoked to justify the use of answers compulsorily obtained in a non-judicial investigation to incriminate the accused during criminal proceedings.7

This is a broad statement of principle. It is not entirely unambiguous, since the Court did not offer a concluded opinion on ‘whether the right not to incriminate oneself is absolute or whether infringements of it may be justified in particular circumstances’.8 But its emphatic rejection of the government’s ‘public interest’ argument is noteworthy.

Two years later the Court had to deal with its first case of entrapment in the context of attempts to bring drug-traffickers to justice. In Teixeira de Castro v Portugal9 the Court found that the applicant had been entrapped by police officers into committing the offence of supplying drugs. One of the government’s arguments was that proactive methods of law enforcement were vital in order to combat drug-trafficking. The Court’s reply reaffirmed the primacy of fair trial rights:

The use of undercover agents must be restricted and safeguards put in place even in cases concerning the fight against drug-trafficking. While the rise in organized crime undoubtedly requires that appropriate measures be taken, the right to a fair administration of justice nevertheless holds such a prominent place that it cannot be sacrificed for the sake of expedience. The general requirements of fairness embodied in Article 6 apply to proceedings concerning all types of criminal offence from the most straightforward to the most complex. The public interest cannot justify the use of evidence obtained as a result of police incitement.10

This is a clear and unqualified statement of the relationship between Article 6 and ‘public interest’ arguments. Fairness cannot be sacrificed to the public interest.

Perhaps the high-water mark of this approach was reached in Heaney and McGuinness v Ireland,11 where the Court held that the applicants’ convictions for the offence of failing to give an account of their movements at a particular time violated their privilege against self-incrimination. The offences formed part of Irish anti-terrorist law, and the government relied on this strong ‘public interest’ argument to claim that curtailment of the privilege against self-incrimination was justified in order to protect the public from terrorist attack. The Court’s response was uncompromising:

The Court… finds that the security and public order concerns of the Government cannot justify a provision which extinguishes the very essence of the applicants’ right to silence and their right not to incriminate themselves guaranteed by Article 6(1) of the Convention.12

Once again, the Court re-affirmed the priority of the guarantees of a fair trial in Article 6 over arguments based on some asserted13 public interest.


In recent years the Court has been confronted with a range of different situations in which governments have pressed arguments based on the ‘public interest’. Sometimes these arguments are phrased in terms of proportionality, a term with several applications in ECHR jurisprudence. As previously noted, the doctrine of proportionality is mostly relevant when determining the justification for interferences with qualified rights such as those in Articles 8–11.14 Very few judgments on Articles 5 or 6 regard it as relevant. When the notion of proportionality is introduced into discussions of the limits of Article 6 rights, the purpose is typically to repackage ‘public interest’ arguments in a form cognisable to the Court. The very same arguments that were dismissed in the three judgments quoted in the previous Section are now being regarded by the Court as relevant in certain circumstances.

In O’Halloran and Francis v United Kingdom15 the question was whether the offence in English law committed by a motorist who fails to comply with a police officer’s request to identify the driver of a vehicle at a particular time is compatible with the privilege against self-incrimination guaranteed by Article 6. The Grand Chamber of the European Court of Human Rights answered affirmatively, concluding:

Having regard to all the circumstances of the case, including the special nature of the regulatory regime at issue and the limited nature of the information sought by a notice under section 172 of the Road Traffic Act 1988, the Court considers that the essence of the applicants’ right to remain silent and their privilege against self-incrimination has not been destroyed.16