A MUG of tea, untouched, grows cold as Derek Acorah outlines his beliefs, and says why he has asked the Sunday Herald all the way down to Soham in Cambridgeshire.

“I wanted you to see what went on prior to and during these shows – what the technical lads do, and who they talk to and don’t talk to before it starts.

“There’s no jiggery-pokery, there are no plants in the audience. I’m an honest man, never mind an honest medium. What I do is to the best of my ability. There’s nothing really set in stone in the sense of accuracy, or how we go on one night. That depends on the spirit people and their communications.”

Acorah had taken the highly unusual step of inviting the Sunday Herald to his show in Soham on Friday night in the hope of establishing that his methods are all transparent – that he isn’t a cheat.

What prompted this rare opportunity for psychic investigation was the recent row concerning Sally Morgan, so-called “Britain’s best-loved psychic”, who has been embarrassed by claims that she was fed information by technicians at an appearance in Dublin. Morgan has since announced on Facebook that she has put the matter in the hands of libel lawyers.

Twice in his Soham show, Acorah says that if Morgan is proved to have done wrong she should stand down. But in her defence the psychic, who earns his living communicating with the dead, claims that people shouldn’t believe everything they read in the papers. As far as the Sunday Herald could work out, though, there were no technical shenanigans during Acorah’s own show.

Referring to the allegations about Morgan, he says: “If something was proven, whether it’s her or any other medium, I think they should immediately step down, because it has tarnished all mediumship, right across the world, especially given the profile the lady [Morgan] has had.

“But if there is no guilt at all, my heart goes out to her, because I’ve known, in the 30-odd years I’ve worked in the world of spirits, that certain accusations have hit every medium.”

Including yourself? “Including myself,” he acknowledges, “because we’re in the public eye.”

Six years ago, a parapsychologist, Dr Ciaran O’Keeffe, who worked on the Most Haunted TV show – the programme which made Acorah a household name – alleged that the medium had pretended to communicate with spirits and obtained details about “haunted” locations before filming.

Acorah said the allegations had tarnished his reputation. He has been considering court action over them.

He gives short shrift to critics such as Professor Christopher French, claiming he “has a pretentious ability to undermine and hurt the person he’s talking about ... He doesn’t conduct himself in the correct manner”.

Acorah is proud of his own approach to shows – or “demonstrations” – such as tonight’s. “One night is never the same as the next. The depth and the accuracies sometimes are different.”

He says he makes a point of going directly to the audience member being sought out by the spirit. “I don’t farm it out. I don’t go, ‘I’ve got so-and-so here, waiting for someone to put their hand up.

“Invariably, nine times out of 10 I’ll get off that stage and go directly to that person, even if they haven’t put their hands up. That’s what I do. I’m the only medium in the world doing it today. I’m very proud of it.”

Does he think claims by spirit mediums, that they can talk with spirits, risk engendering hope in some bereaved people that their loved ones are not in fact dead, but still active in some realm?

“Some mediums don’t talk about the system of things, what happens when you have to let go – when we pass over, die. Is it the end or is there something else for us?

“If your belief system through knowledge is thorough, your belief system should be that there is set aside for us another life. We’re all part of a great scheme of eternal life. It doesn’t have to be religionised.

“My proof over the years is so strong that no-one will ever take it away from me. No-one can ever convince me that there is no such system in place. I do believe it’s my vocation, and has been for a lot of years, to convey communications to loved ones who have been bereaved, or people who haven’t really understood that there has been an afterlife.”

He is touched by the number of people who stay behind after his shows in order to talk to him. “They’ll say, I came here with my wife or girlfriend, I didn’t really want to come here tonight, I didn’t believe in this, but you have shown me. You told me things about my father, you told me about his personality.”

He says he has learned to switch off when away from the stage – it would be too draining if the “spirit people” came at him 24 hours a day.

“I open up to the world of spirit when I’m working for the world of spirit, but when I’m being a husband, father, grandfather, I’m an ordinary man. I’ve got ordinary responsibilities, just like any other man.

“But when I go to work, I put on, if you like, a different head, and I have to make sure I’m feeling at my best.”

He firmly rejects any idea his beliefs - including his initial incarnation 2000 years ago, in Sam, his Ethiopian spirit guide – are merely part of an elaborate stage routine, to be packed away along with the stage suit once the show is over.

It’s easy for sceptics to mock people like Acorah for such beliefs, but he has never been shy about articulating them, and they seem to be part of who he is. He had invited the Sunday Herald to check he is transparent. There didn’t seem to be any underhand methods on display – but it is still hard to explain how exactly he does what he does. Unless you accept his own explanation at face value.