Andrew Morton, the man behind Diana’s secret tapes, suffered a suspected stroke while on stage at a book signing event in central London this afternoon.
The biographer was performing a speech about his book “Wallis In Love: The Untold True Passion Of The Duchess Of Windsor” when the incident happened.
The 65-year-old told the shocked audience at Simpson’s In The Strand: “I’m sorry I can’t go on.”
He was then rushed to the University College London Hospitals seeking urgent treatment.
A source at the event said: “Andrew was five minutes into his speech about Wallis Simpson when he lost concentration.
“He forgot what he was saying, was sweating and started to sway. He ended up getting carted off from The Strand in the back of an ambulance and taken to UCLH.
“People are saying it’s a suspected stroke.”
Morton has since posted an update on his condition on Twitter, announcing he is now “on the mend”.
He said: “Thank you for all of your good wishes – seems that I had a mini stroke, but am doing well & on the mend.”
Morton made his name worldwide when he penned “Diana: Her True Story”, which was was revised after her death in the horror car crash in Paris in 1997.
The book came off the back of seven hours of taped interviews which were secretly made in Kensington Palace in 1991 and conducted between him and Diana through an intermediary.
In the tapes, the Princess dropped massive revelations which shook the Royal Family to its core – from Prince Charles’s affair with Camilla to her battle with bulimia and suicide attempts.
Morton, who recently published “Meghan: A Hollywood Princess”, was due to help present ABC’s coverage of Meghan Markle and Prince Harry’s Royal Wedding this weekend.