AI is concerned about reports alleging that some prisoners in Schrassig Prison have been kept in total isolation for long periods of time. AI fears that this may have serious effects on the physical and mental health of prisoners. One prisoner, Jean-Marc Mahy, a 25-year-old Belgian citizen, has told AI that he was held in total isolation from April 1987 to March 1990. Carlo Fett is believed to have been in isolation for 48 months and two others, Nico Reisdorff and Joseph Bernardy, for 39 months. Solitary confinement is used for disciplinary purposes or where a prisoner is classed as dangerous. According to regulations issued in December 1991, prisoners who have used or possessed drugs in prison may be placed in isolation. AI’s correspondence with the authorities is summarized.