Former royal butler Paul Burrell said he was "sick to his stomach" when he received a phone call from a man saying he had kidnapped his wife, a court has heard.
Chester Crown Court was told that Burrell had been the victim of threatening phone calls made to his business in which the caller also threatened to place an "incendiary device" at his flower shop.
Burrell, 53, was giving evidence in the trial of Slav Mitev, 50, who is charged with harassment and causing a victim to be put in fear of violence.
However, Judge Elgin Edwards, The Recorder of Chester, ruled on Tuesday that Mitev, of Station Road, Wood Green, London, was not fit to enter a plea to the charges due to his mental state.
Judge Edwards told the jury of seven men and five women that they just had to come to a decision about whether or not he was guilty of the acts alleged.
Taking to the witness stand, Burrell, wearing a pin-striped suit, blue shirt and yellow tie, re-lived a number of phone calls which were made to Paul Burrell Flowers in Farndon, near Chester, in June and July last year.
In one call, the person on the other end of the phone made threats to set his shop - where he was living at the time - on fire.
Mr Burrell told the jury: "The caller said 'have you got a pen because I want you to write this down. I am going to use an incendiary device. Do you know how much shattered glass there will be in your shop?'"
Asked by Gordon Hennell, prosecuting, if he took the call seriously, Burrell responded: "I certainly did."
He then received another call just a few minutes later which he said was the "most disturbing" because it referred to his wife Maria.
"I do remember this call because it was the most terrible. It started by him saying, 'Maria, Maria?'
"I said Maria is my wife's name. And I said to him, 'you know that Maria isn't here'. I said she is in America. He said, 'no she's not. Can't you hear her?' he said.
"And what I could hear in the background was a woman sobbing and someone crying saying 'please help me, help me please.'"
Mr Burrell added: "I can honestly say that I was sick to my stomach. I put the phone down and immediately rang my wife in America. My thought was that maybe he was calling from the States and that he had managed to get into my home and had my wife in custody."
Mr Burrell, who told the court he had property in America, said his wife answered and said "what on earth's the matter?"
The court heard that Mr Burrell began taking notes of what the caller was saying.
He said the impression he had was of a "mature man" in his 50s with an "Asian sounding voice."
The court heard about other calls made to the flower shop in which the caller said he was masturbating. At one point he asked: "How much money did you extort from the royals?" and if he still kept his "photographs from Hyde Park".
Mr Burrell said before the threat about the incendiary device there was a threat about setting his shop on fire.
He said: "During that call he said, 'there is going to be a big fire. I hope you have a fire brigade nearby'."
The former butler said that 10 years ago his previous flower shop had been the subject of an arson attack.
"I was very nervous at that point and thinking 'my goodness it's going to happen again'."
Mr Burrell then went on to describe the moment when he confronted the caller after he made threats about his two sons and about "blowing up a plane" which his brother was travelling on.
He said: "The caller said we had known each other for 27 years. I said to him, 'why are you doing this? Why do you hate me so much?' He said he didn't hate me, he loves me."
At this point Mitev, wearing a suit and red overcoat, smiled and shook his head.
The court heard Mr Burrell reported the matter to the police who alerted British Telecom who in turn traced the calls to Mitev's mobile phone.
Mr Hennell said Mitev was arrested in London on 2 July and denied making the phone calls.