As for Derek Acorah...(from The Daily Thingy).
"Ciaran, who joined Most Haunted in April 2004 became suspicious of Acorah's antics on a shoot at Castle Leslie, Co Monaghan in Ireland where a 17th Century four-poster bed has been claimed to levitate.
Ciaran recalls: "As we walked into the bedroom, Derek touched the bed and came out with extremely accurate information.
"He insisted he got all the information just from touching the bed. But it was the wrong bed."
Antix Productions claims the mediums have no idea where they will be filming or know any details about the history of the locations.
But Ciaran says: "Derek must have had prior knowledge of the locations."
He devised a plan to see if Derek was deliberately deceiving the public.
While on a shoot at Bodmin gaol he invented a long-dead South African jailer called Kreed Kafer - an anagram of Derek Faker.
"I wrote the name down and asked another member of the crew to mention it to Derek before filming.
"I honestly didn't think Derek would take the bait. But during the filming he actually got possessed by my fictional character!""