Their methods have been scoffed at and their claims to be in touch with an afterlife taken with more than a pinch of salt – but a five-year test has shown that mediums can indeed discover your deepest secrets.

Researchers at the Scottish Society for Psychical Research (SSPR) say mediums who took part in their tests beat odds of a million to one to correctly reveal information about volunteer test subjects.

Tricia Robertson, vice-president of the SSPR, a registered charity with around 250 members, said: “We were not trying to prove the existence of the afterlife or that personalities live on, but I think it is now important to recognise that mediumship can honestly gain information that ordinary people can’t.

“I would welcome more academic research into this because it is an area where activity is unexplained as yet.”

A total of 13 mediums took part in the SSPR study, carried out in Scotland and London. In each test the medium would sit in a different room from the participants and choose seat numbers they wanted to read from the audience. The audience, usually around 30 people, would enter a room out of sight of the medium and on their way in be given a random seat number. After the reading, adjudicators would distribute lists of what the mediums had seen and the audience had to tick which of the mediums’ statements applied to them.

The rules of chance would suggest an accuracy rating of 30%, but the mediums’ average was 70%, with some hitting 80% on some of the participants.

“The results were very surprising,” said Robertson. “I have no idea how mediums can gain this information but the results prove that able mediums can accurately read their subjects. Their chances of guessing this level of information about their subjects is a million to one, statistically.

“I am aware that critics will say the tests were somehow rigged. But, rest assured, we could not have been more scientific in the way this was carried out. If anyone claims it is fixed or rigged, we would sue.”

Robertson is due to present her findings, which have been peer reviewed and published in the Journal Of The Society For Psychical Research, at the International Paranormal Conference at Muncaster Castle, Cumbria, this weekend.

Glasgow’s famous “psychic barber” Gordon Smith was one of the mediums who took part in the study. He said: “The conditions were very strict – I had to arrive an hour before the participants and never got to see them. While, for me, it is not essential to be in the same room as the participants, the work is very credible because of those test conditions we were working under.”

Professor Richard Wiseman, a noted psychologist at the University of Hertfordshire who studies the paranormal, said he was unconvinced by the SSPR’s test results.

“It could be true, but testing mediums is notoriously difficult to do well and I’m not entirely convinced that a figure of 80% would be accurate,” he said.