As I indicated earlier, the fundamental problem with these legal instruments is that, when they are implemented, the authorities restrict fundamental rights that are also protected by the Convention.2 At the same time, there are rules in force in all the Member States under which these restrictions on fundamental rights may be disregarded on the grounds of law enforcement interests, but only

The general authorisation to use disguised means is derived from Article 8 of the Convention, which allows the authority to interfere with the inviolability of certain fundamental rights if it is necessary for reasons of national security, public security, public health, morality, the economic well-being of the country or the prevention of crime.3 It can therefore be concluded that the use of these legal instruments can be considered legitimate from the point of view of European law, even if they are not accompanied by prior or subsequent judicial authorisation. I would point out that, in my view, any procedural act involving a restriction of a fundamental right would require at least some form of judicial authorisation to be obtained ex post. As Király puts it, “a judge’s authorisation as a condition is intended to insert an impartial, unbiased person between the police and the person who suffers the measure […].” 4

Under Hungarian law, a disguised instrument may be used if

As regards the personnel involved in the use of covert means, the concepts of informer, confidential person and undercover investigator should be clarified. The only common feature of these subjects is that their identity or capacity as such remains unknown to the persons under surveillance during the procedure. Beyond this, however, there are substantial differences in terms of (1) the permanence and nature of their activities, (2) their organisational affiliation, (3) their level of loyalty – reliability – risk factors and (4) the rules for authorising their employment.

In relation to the proceedings of persons belonging to group c), the Court has recently received a number of petitions which have criticised (1) the sanctioning of offences committed at the provocation of undercover investigators and (2) the complete “procedural anonymity” of such investigators and, therefore, their exclusion from evidence. On this basis, the Strasbourg forum found a violation of the Convention in the following case: