A special police unit was set up after research revealed more than 80 per cent of stalkers who followed members of the Britain’s royal family had serious mental illnesses.
The Fixated Threat Assessment Centre was secretly established two years ago after a study showed that in 20,000 cases between 1988 and 2003, a huge majority of offenders suffered from conditions including schizophrenia, delusions and hallucinations.
Around 200 of the stalkers suffered from psychosis, a serious mental condition which causes the sufferer a “loss of contact with reality”.
The unit has seen 320 referrals – resulting in 10 detentions – and has the power to hold suspected stalkers or send them to a psychiatric hospital.
Paul Mullen, of the Victorian Institute of Forensic Mental Health in Australia which completed the original study, told New Scientist magazine: “We didn’t expect such high rates of psychosis. It was very surprising to us.”
He added: “People who stalk royalty may show a strange mixture of affection and the belief that they are a relative – or even the rightful heir.”
Half of the 20,000 stalkers had written explicit love letters or made death threats.
One high-profile stalker, 57-year-old Michael Fagan, broke into the queen’s bedroom and sat on her bed chatting to her in 1982.
He was once arrested for standing outside the late Princess Diana’s home dressed in combat gear and carrying a knife and rope.