The use at trial of such evidence will generally not violate the fairness requirements if proper procedural safeguards are in place and if the reliability of such evidence is not tainted by e.g. oppression, coercion or entrapment (see notably Schenk against Switzerland, No. 10862/84, judgment of 12 July 1988, ??46; and Khan against the United Kingdom, No. 35394/97, judgment of 12 May 2000, ??34).