James Andanson, who followed the Princess’s every move in the week before her death, was thought to have committed suicide when his burnt corpse was found in the wreckage of a car in the French countryside.
But now the fireman who discovered the body, Christophe Pelat, has said: “I saw him at close range and I’m absolutely convinced that he had been shot in the head, twice.”
The revelation threatens to blow apart the inquest on Diana, which will have another preliminary hearing today in the London High Court.
Harrods owner Mohamed Al Fayed, whose son Dodi, 42, died with Diana in a Paris crash, is now demanding that Mr Pelat be called to give evidence at the inquest – or at least that his account is heard.
Andanson, 54, has been one of the key figures in the mystery surrounding the fatal crash, which happened 10 years ago next month.