The forensic pathologist who worked on Princess Diana’s inquest has a stern message for conspiracists – and it’s simply that they’re wrong.

Dr Richard Shepherd is widely regarded for performing high-profile autopsies and has worked on a number of notable investigations throughout his career, including the victims of 9/11 and 7/7, the death of Stephen Lawrence, the Hungerford massacre, the sinking of the Marchioness and the Bali bombings.

However, the one case he gets asked the most about by those fascinated by his career is, as to be expected, the tragic death of Diana, Princess of Wales, in August 1997.

The expert, who has examined more than 23,000 bodies, was called in as a consultant to give evidence at the inquiry and review the autopsy.

Recalling the job, he told Tyla: “It’s like standing in the middle of a thunderstorm. Because you know, there’s everything coming down at you and flashes and bangs. But it was very interesting. We had a critical job to do.”

For those who need a reminder, Diana was just 36 years old when she died following a car accident in Paris, France.

The mother-of-two was travelling through the Place de l’Alma underpass in central Paris in the back of a Mercedes-Benz S280 with Egyptian film producer Dodi Fayed.

The pair were joined by Dodi’s bodyguard, Trevor Rees-Jones, and were being driven in the armoured vehicle by Henri Paul, who was later found to have been intoxicated by alcohol and under the effects of prescription drugs.

Diana was initially conscious after the crash, but she quickly fell into cardiac arrest and, during surgery, medical staff were able to identify that the problem was a small tear to a vital vein, a pulmonary vein, which ultimately caused her death.

As well as questions about the tragedy, another thing that Dr Shepherd has been inundated with is conspiracy theorists’ wild questions and claims.

Ever since the royal’s unexpected death, the case has divided the world, with some people convinced it was more than just a tragic accident. Some people were so set on this view that the Met Police were forced to conduct an investigation into the death and rule them out as untrue – this was called Operation Paget.

Ultimately, it found no evidence of conspiracy and concluded that Diana and Dodi’s deaths were tragic accidents.

Although there is not a shred of evidence that supports it, one of the most widespread conspiracies is that the British Royal Family were somehow involved in Diana’s death and allegedly orchestrated that night’s fatal crash.

When asked about what he’d say to people who still believe this, Dr Shepherd responded: “Well, I’m afraid I would just shrug my shoulders and say, ‘Well, you’re wrong.’

“You know? And the point is it’s always possible to take 20 facts and knit them together into some sort of story.”

He elaborated: “‘Well, explain that. Why was it the 13th pillar in the tunnel?’ Well, that’s random, you know, it is just one of those things. And if you are a member of the Prince Philip Assassination Squad, you wouldn’t deliberately crash them into the 13th pillar. You’d do something else.”

He explained that the theory ‘doesn’t hold water in the context of what was going on’ and pointed out the known facts.

“Henri Paul was drunk, Henri Paul wasn’t skilled at driving, Henri Paul was determined to outrace these people, possibly with Dodi in the back, going, ‘Just go faster, just go faster,” the expert said. “You know, you can imagine the situation that was evolving, and a bad driver, part drunk in a car at that speed, is not going to end well.”

Discussing what it was like working on the high-profile case at the time, Dr Shepherd said he was ‘busily conscious of the rumours that were spreading the theories that were spreading’.

He said: “It was a combination of quite exciting, very interesting, quite exhilarating to be there, and yet the conscious thing was that you knew anything you said was going to be challenged by one group or another. I mean, whatever you said, someone was going to say, ‘you got it wrong’.”

The expert also revealed that tragically, had Diana worn her seatbelt, she may have walked out of the crash alive.

He explained: “She may have had a broken rib. She may have had a broken arm, but she would actually have walked out of that crash, I mean, it’s a bad crash, admittedly, but it’s not that bad, you know, and Mercedes are designed to take these bumps.

“How tragic is that – the one one click that would have saved her life?”