Methodsclinicalinformationof602cases ofnevusof Ota were collected by applying clinical records, checkingphotos, and inquiry to patients by letters and telephones.
The hoaxer, who had an accent said to be from the Castletown area of Sunderland, sent police three letters and an audio tape at the height of the Yorkshire Ripper inquiry in 1978 and 1979.
Mr Tyrie, the MP for Chichester, claimed the letters were not released to Sir Anthony Hammond QC, who conducted the passport inquiry that cleared ministers of wrongdoing.