Psychic Sally Morgan hears voices from the other side (via a hidden earpiece)

According to her website, Sally Morgan is "Britain's best-loved psychic". She is certainly a very successful psychic – she has just released her third book and is currently filming the third series of Psychic Sally on the Road for Sky LIVING. But an incident that took place a few days ago may cause a few of her fans to wonder whether Morgan is deserving of their adoration. Could it be that, like so many self-professed psychic superstars in the past, Morgan is nothing more than a self-serving con artist?

Let me describe what happened so that you can make up your own mind. On Monday 12 September, a caller named Sue phoned the Liveline show on RTÉ Radio 1, an Irish radio station. Sue said that she had attended Morgan's show the previous night at the Grand Canal Theatre in Dublin and had been impressed by the accuracy of the readings she made in the first half of the show.

But then something odd happened. Sue was sitting in the back row on the fourth level of the theatre and there was a small room behind her ("like a projection room") with a window open. Sue and her companions became aware of a man's voice and "everything that the man was saying, the psychic was saying it 10 seconds later."

Sue believes, not unreasonably, that the man was feeding information to Sally through an earpiece attached to her microphone. For example, the voice would say something like "David, pain in the back, passed quickly" and a few seconds later Sally would claim to have the spirit of a "David" on stage who – you'll never guess – suffered from back pain and passed quickly.

A member of staff realised that several people near the back of the theatre were aware of the mystery voice and the window was gently closed. The voice was not heard again.

Sue speculated, again not unreasonably given the history of psychic frauds, that the man was feeding Sally information that had been gathered by engaging members of the audience in conversation in the foyer before the show began. This is a technique widely used by psychic fraudsters, as audience members will naturally discuss with each other who they are hoping to hear from "on the other side", how their loved one died, and so on.

Subsequent callers to the radio programme supported Sue's account.

The theatre's general manager, Stephen Faloon, claimed that the voice heard by the audience was actually the voices of two members of staff working for the theatre, not someone supplying information to Sally. Sally Morgan Enterprises also denied that the medium was being fed information during the show.

This episode is reminiscent of the exposure of faith healer Peter Popoff by James Randi in 1986. Popoff would wow his audiences by giving specific and accurate details of their medical problems before claiming to cure them with his divine powers. This information was, according to Popoff, provided to him directly by God. It was certainly an effective technique, as at this time Popoff was raking in around $4m per month (tax-free) from his poor, sick and uneducated followers.

Randi, with the assistance of investigator Alexander Jason, convincingly demonstrated that Popoff was actually receiving the "divine" information from his wife via a hearing aid. Following his exposure on The Tonight Show Starring Johnny Carson, Popoff declared bankruptcy in 1987.

In a more rational world, that would have been the end of Popoff's career as a faith healer. Sadly, we do not live in a rational world. Popoff is back, earning more than ever by fleecing his flock using exactly the same techniques that Randi exposed, plus a few new ones, such as the sale of "Miracle Spring Water". According to ABC News, Popoff's ministry received more than $9.6m in 2003 and more than $23m in 2005. In that year, Popoff paid himself and his wife a combined total of almost a million dollars (not to mention two of his children receiving more than $180,000 each).

Since the heyday of mediumship during the Victorian era, exposure as frauds has typically done little to diminish the popularity of alleged psychics in the eyes of their followers.

It is important to realise that many self-professed psychics, possibly the majority, are sincere in their beliefs that they possess a "gift". Such practitioners are probably unintentionally using some of the same techniques used by so-called cold readers to convince themselves and their sitters that they are tapping into some paranormal source of information. Because the cold reading technique is not being exploited deliberately and systematically, such readings are usually unimpressive to anyone except hardcore believers.

But con artists can use cold reading to convince complete strangers that they know all about them. It relies on the clever use of language, careful observation, intelligent guesswork, and the production of vague and ambiguous statements that the sitter interprets (and remembers) as being more specific than they actually were. In a skilled practitioner, cold reading can produce much more impressive results than the rather amateurish readings produced by most psychics.

Read more at The Guardian