European Court of Human Rights - case of Van Mechelen and Others v. The Netherlands (1997) (excerpts)

European Court of Human Rights - case of Van Mechelen and Others v. the Netherlands   (1997) (excerpts)

(...)

51.   In addition, all the evidence must normally be produced at a
public hearing, in the presence of the accused, with a view to
adversarial argument.  There are exceptions to this principle, but they
must not infringe the rights of the defence; as a general rule,
paragraphs 1 and 3 (d) of Article 6 (art. 6-1, art. 6-3-d) require that
the defendant be given an adequate and proper opportunity to challenge
and question a witness against him, either when he makes his statements
or at a later stage (see the Lüdi v. Switzerland judgment of
15 June 1992, Series A no. 238, p. 21, para. 49).

(...)

54.   However, if the anonymity of prosecution witnesses is maintained,
the defence will be faced with difficulties which criminal proceedings
should not normally involve.  Accordingly, the Court has recognised
that in such cases Article 6 para. 1 taken together with Article 6
para. 3 (d) of the Convention (art. 6-1+6-3-d) requires that the
handicaps under which the defence labours be sufficiently
counterbalanced by the procedures followed by the judicial authorities
(ibid., p. 471, para. 72).

55.   Finally, it should be recalled that a conviction should not be
based either solely or to a decisive extent on anonymous statements
(ibid., p. 472, para. 76).

(...)

57.   On the other hand, the Court has recognised in principle that,
provided that the rights of the defence are respected, it may be
legitimate for the police authorities to wish to preserve the anonymity
of an agent deployed in undercover activities, for his own or his
family's protection and so as not to impair his usefulness for future
operations (see the above-mentioned Lüdi judgment, p. 21, para. 49).

 58.   Having regard to the place that the right to a fair
administration of justice holds in a democratic society, any measures
restricting the rights of the defence should be strictly necessary.
If a less restrictive measure can suffice then that measure should be
applied.

(...)

63.   Moreover, the only evidence relied on by the Court of Appeal
which provided positive identification of the applicants as the
perpetrators of the crimes were the statements of the anonymous police
officers.  That being so the conviction of the applicants was based "to
a decisive extent" on these anonymous statements.