Mr McKenna, a bestselling author on hypnotherapy, is suing the Daily Mirror for libel over a “spiteful” article by the columnist Victor Lewis-Smith published in October 2003.

He told Mr Justice Eady in the High Court: “Commercial competitors and practitioners have seized on the article and mocked me. My peers made jokes about the article and I became a laughing stock. People were whispering about me behind my back saying I was so vain that I had bought a doctorate in America.”

The article was the ninth repetition in the Mirror and the Evening Standard of allegations first made by Mr Lewis-Smith six years earlier — and he was “devastated”.

Mr McKenna, 43, told the hearing: “I am a public figure and from time to time I expect to be criticised in the press. However, what was written about me is a lie. Furthermore, Mr Lewis-Smith has apparently decided to repeat these allegations on something like an annual basis . . . since he first made them in 1997 in his Evening Standard article.”

The court has been told that he was awarded the doctorate from Lasalle University in Louisiana but that its principal, Thomas Kirk, who was later jailed for five years, had cheated innocent students. Kirk had made them believe that their degrees were accredited by a recognised body — the so-called Council for Post-Secondary Christian Education — which turned out to be his own fraudulent creation.

In an article in the Mirror, Mr Lewis Smith wrote that the only requirement for a Lasalle doctorate was to answer correctly the question: “Do you have $2,615, sir?” Mr McKenna said yesterday that he did not know about the fraud until he had submitted his final dissertation of 70,000 words and spent 500 hours on study and coursework.

Cross-examined by John Kelsey-Fry, counsel for Mirror Group Newspapers, Mr McKenna, who suffers from dyslexia, admitted that he had only two O levels, one CSE and an A level in art.He had decided against applying to take a first (Bachelor’s) degree after determining that a PhD was more in keeping with his experience in hypnotherapy and authorship.

Mr McKenna said he was shocked that the article had been published as he had only just received a retraction in the Evening Standard to another article by Mr Lewis-Smith referring to him as “Non-Doctor”. He said: “I was appalled that he had returned to the subject, which seemed to me to be an act of spite. I felt humiliated and disgusted. I was very hurt as it depicted me as a fraudster who knowingly had bought a degree to defraud the public.

“I worry that as a result of the article people will question not only whether I am telling the truth about my academic qualifications but also about my integrity as a hypnotherapist, broadcaster, author and trainer.”

He added that he had never believed that his degree was bogus.

The case continues today.

Times Recommends

• Clifford Chance sets out to improve its public image
• Bennett starts 16-year sentence for Refco fraud
• FSA challenged over insider trading case