Princess Diana's former lover James Hewitt was last night reported to have been fighting for his life after suffering a heart attack and a stroke.
The 59-year-old former Army officer had needed emergency surgery and doctors gave him "a slim chance" of survival, according to reports.
He is now said to be recovering, reported the Daily Mail.
News of his illness comes just weeks after he gave a rare interview denying longstanding rumours he is Prince Harry's real father - a slur repeated again in the new BBC2 drama King Charles III.
Hewitt was said to be undergoing treatment at the Royal Devon and Exeter Hospital, where he is expected to remain for several weeks.
Friends said he fell ill two weeks ago and was rushed to Derriford Hospital in Plymouth to receive care from specialist medics.
A relative told a Sunday newspaper: "The family were concerned. He had a pre-existing illness, then got seriously ill. Suddenly it got very critical and he was rushed to hospital.
It was pretty serious but hopefully we are all OK now.
"He is recovering and has been moved to Exeter."
The ex-Army captain and Gulf War veteran had a five-year affair with Diana while she was married to Prince Charles.
The pair met at a party in London in 1986 when she was aged 25. He was 28.
Three years later - in a now iconic image at the height of their affair - she was pictured presenting the Life Guards officer with a polo trophy.
The couple were forced apart when he was sent to Iraq in the 1991 Gulf War and split after their affair was made public.
Hewitt now lives with his widowed mother Shirley in a two-bedroom flat in Exeter.