‘The injury Diana suffered was so rare – I’ve never seen another one like it’

One of Dr Shepherd’s saddest and most high-profile jobs was the public inquiry into the death of Diana, Princess of Wales, eight years after she was killed in a car accident in Paris.

‘It was an honour to be asked to assist such an important inquiry, but I also realised what a crucial job this was, which meant I was under a lot of pressure. It was very technical in places, working out what happened in the micro-seconds of the crash and linking this with her injuries. Diana suffered a tiny tear in a vein in one of her lungs that was bleeding very slowly. She lost consciousness and was taken by ambulance to the hospital where surgeons identified the vein and repaired it; sadly, it was too late. The injury she suffered was so rare that I’ve never seen another example in my career. It was a small injury in the wrong place, which was caused by her catapulting forward from the back seat. It’s sad to think that had she fastened her seatbelt, she would probably have only suffered a black eye and had her arm in a sling – and would have been at her sons’ weddings.’

• Unnatural Causes by Dr Richard Shepherd (Michael Joseph) is out now