A decade on from the tragedy, there remains enormous sympathy for the grieving Harrods tycoon.

Yet by his own admission, the Egyptian billionaire only found out that Diana was pregnant and that the couple were engaged in a phone call from them just one hour before their car crashed in the Alma tunnel in Paris at 12.23am on August 31, 1997.

It did not leave much time, Mr Horwell said to organise a carefully-disguised and wide-ranging assassination plot and cover-up, involving Mr Andanson driving a white Fiat Uno, which witnesses said had a dog in the back seat.

“Prince Philip has to be told, Prince Philip has to issue the order, “ he said. “MI6, MI5, the French security services, CIA, the ambulance service, the French doctors, the French scientists, James Andanson and his dog, all have to come together within a matter of moments, Mr Al Fayed, to kill Diana and Dodi.”

At that moment, it was clear the game was up. Until then it had seemed possible that there might be enough doubts for jurors to go for an open verdict on the grounds that there were so many unanswered questions.

The plain fact, however, is that after 10 years of separate multi-million pound inquiries by police in Britain and France as well as Mr Al Fayed’s own investigators, not a scrap of direct evidence has emerged to support the conspiracy theories.

Amid the vast cast of characters involved in the supposed plot, not a single person, from humble ambulance workers to policemen and statesmen has broken ranks to reveal the scale of the crime. Some named by Mr Al Fayed were not even there. Diana’s brother-in-law, Lord Fellowes, then the Queen’s private secretary, was said to have been in Paris that night, masterminding the assassination plot from the British embassy’s communications centre.

But he told the inquest: "We were in Norfolk that evening. We had people to stay. We went to an entertainment by Mr John Mortimer in Burnham Market Church."

Faced with the reality of their weak case, even Mr Al Fayed’s own legal team, under a professional duty to only make serious allegations against people with sufficient evidence, were forced to abandon the central planks of the tycoon’s murder plot.

Instead, they clung to the claim that Prince Philip created such a climate of hostility towards Diana that – like the four knights who killed Thomas Becket after Henry II moaned “Who will rid me of this troublesome priest?” – rogue MI6 officers must have taken matters into their own hands and tried to frighten or injure the couple.

But there was no evidence to support that either.


DIANA’S FEARS

Princess Diana certainly expressed fears that the Royal Family were out to get her and at times told friends that her principal enemy was Prince Philip. She also complained that Prince Charles wanted her out of the way so that he could marry again. The Princess predicted that an accident would be arranged for her in a car.

But, isolated after her marital break-up and increasingly reliant on a weird collection of fortune tellers and soothsayers, she also expressed fears that many other people were out to kill her, including the CIA and Arabs, in a plane, helicopter, or simply by shooting her in a London park.

In a note recording her thoughts to Paul Burrell and a similar one made by her lawyer Lord Mishcon, she suspected her husband wanted to marry his sons’ nanny Tiggy Legge-Bourke rather than Camilla. Other predictions, that the Queen would abdicate in 1996 and Prince Andrew would be made regent until Prince William came of age, for example, did not come true.

Philip was said to have written nasty letters to her but the only letters from him, in an exchange of missives from June to October 1992, proved to be an attempt by him to help Diana resolve her marital problems with Charles. There were claims there were other nastier letters but Philip denied their existence and no trace of them exists.

Diana also feared her home, car and phones were bugged by the security services. Many experts think it likely but, despite many claims, there is no concrete evidence. It has never been established who did record the one call that definitely was bugged, her infamous 1989 Squidgygate conversation with her suspected lover James Gilbey.

Mohamed Al Fayed told how during his holiday with Diana in St Tropez in July 1997, she confided her fears that she would be assassinated. But the coroner said: “If he thought there was anything in the fears, why were there only two bodyguards provided by him?”
 

ESTABLISHMENT FURY OVER DODI AFFAIR

It is certainly true that the Royal Family and many others in the British Establishment regarded Diana as a loose cannon and were horrified by her romance with Dodi Al Fayed because of his father Mohamed’s controversial business record. But, as with any bugging that might have happened or assassination fears expressed by the Princess, the coroner suggested it was a bridge too far to then say, without any direct evidence, that Diana must have been murdered.

Besides, if Philip really was concerned about Diana marrying a Muslim, why had he done nothing to stop her two-year romance with another Muslim, heart surgeon Hasnat Khan?

 

DIANA PREGNANCY

In spite of Mohamed Al Fayed’s claims that Diana told him she was pregnant, a wide range of witnesses came forward to say that the Princess was on the contraceptive pill, had her period in mid-August, and would not have got pregnant outside of marriage. Claims that the Princess’s body was illegally embalmed to cover up the pregnancy were dismissed: the French obtained the necessary permission to embalm Diana’s body to stop it decomposing in the heat of a hospital room and make it more presentable for a visit by Prince Charles and President Jacques Chirac. Pathologist Robert Chapman, who performed a post mortem in Britain, said embalming would not have stopped him detecting a foetus. He looked for one and there was no sign, the inquest heard.

 

ENGAGEMENT

Lord Justice Scott Baker remarked that nobody would ever know for sure if Diana and Dodi were about to get engaged. Their relationship certainly seems to have been more serious than many of Diana’s friends have claimed. Hasnat Khan’s revelation that Diana dumped him for Dodi was devastating to their case.

There are doubts, however, about whether Dodi really did propose to Diana, using an £11,500 ring from a range called Tell Me Yes. Alberto Repossi, the jeweller who claimed to have met the couple in St Tropez to show them the ring and then sent it away to Italy for resizing, was an unconvincing witness who admitted lying and failed to provide promised documentation to support his claims.  

 

THE CRASH

The easiest way to look at the futility of the conspiracy case is to work back from the Alma tunnel crash itself, which happened at between 12.22am and 12.23am on Sunday, August 31, 1997.

All sides are agreed that the couple’s Mercedes, driven by Ritz Hotel security manager Henri Paul, was travelling at around 65mph in a 31mph zone when it crashed. It was being chased by paparazzi when it was hit with a glancing blow by a still unidentified white Fiat Uno near the Alma underpass entrance.

 Swerving one way and another, it then ploughed into the 13th concrete pillar, creating a high-energy impact that killed Dodi and the driver immediately and left Diana fatally wounded and their bodyguard Trevor Rees Jones with serious injuries.

If it was an ambush, then the would-be assassins were leaving much to chance. First, if the driver of the white Fiat Uno was deliberately trying to cause the crash then he picked the wrong car and could not have been certain of killing the couple.

“Can you help as to why the might and power of the Royal Family, the British Government and MI6 could only afford a Fiat Uno, one of the world's lightest and least powerful cars?” Mr Horwell asked Mr Al Fayed with withering sarcasm.

Tony Read, the Metropolitan Police’s top accident investigator, told the jury it would have been almost impossible to plan the collision because it would have been difficult to be sure that a small Fiat could seriously damage a much heavier Mercedes.

It was the victims’ bad luck that their car then smashed into a concrete pillar. Had they hit the wall, the after-shock would have been less severe and, crucially, if they had been wearing seat belts, their survival chances would have been almost assured.

 

HENRI PAUL

Mohamed Al Fayed has claimed Henri Paul worked for MI6 and was duped into driving the Mercedes into a trap by his handlers. But although he was an informant for French spies, there is no evidence he ever worked for MI6, according to the intelligence service’s records and testimony.

It appears to have been Dodi’s idea that Mr Paul, instead of his professional chauffeur, Philippe Dourneau, should drive him and Diana from the rear of the Ritz to his flat near the Champs-Elysees in a car without a crucial security back-up vehicle. Without that plan, it is highly unlikely that a crash would have happened.

Mr Al Fayed claimed Henri Paul was fitted up and was falsely portrayed as high on a cocktail of drink and prescription drugs by French scientists who switched his blood samples. He pointed to inexplicable high levels of carbon monoxide in his blood which made the alcohol readings unreliable.

The weight of expert evidence is that, although French tests which appeared to show Mr Paul was three times over the French drink-drive limit (and twice the UK limit) were shoddy and not reliable enough to convict him of criminal offences had he survived, they probably did come from his body. He was also driving at more than twice the speed limit when he crashed.

 

EYEWITNESSES

Various witnesses came forward to say they saw a bright flashlight that might have disorientated the driver, a dark blocking car in front of the Mercedes and one or more motorbikes immediately behind the car as it entered the tunnel.

Some turned out to be fantasists, others may have been genuine and seen something unexplained, but there was nothing concrete to suggest anything sinister happened in the tunnel.

It is entirely possible that there was a bright flash of light, coming from the headlights of cars travelling in the opposite direction or from a paparazzo taking photographs from the back of a pursuing motorcycle. But one witness who should be discounted is Francois Levistre, who claimed to have seen in his mirror two leather-clad motorbike riders shining a bright light into the Mercedes as he was driving ahead of the crash.

Levistre, a petty criminal and conspiracy theorist who has changed his story several times, memorably described the pillion passenger getting off, inspecting the wreckage and then signalling mission accomplished with a sign like a boxing referee counting a fighter out. After giving his testimony, he contacted the coroner to say he had retrieved bullet casings from the tunnel that night but never fulfilled his promise to send them to the inquest.

“Witnesses who give evidence in our courts fall into many different categories, ranging from those at the one end of the scale who are patently honest and reliable to
those at the other, on whose evidence you would not swing a cat,” the coroner said. “The assessment is yours, but my advice to you is that you should linger long before relying on anything that he said.”

 

MI6

Sacked renegade spy Richard Tomlinson claimed MI6 officers were trained on how to use flashlights to disorientate enemies. Drawing parallels with witness reports from the underpass, he wrote in his book how he had seen a 1992 Secret Intelligence Service plan to use bright flashlights to assassinate Serbian President Slobodan Milosevic in a Geneva road tunnel and make it look like an accident. He also said he recalled seeing a file on an MI6 agent, a Frenchman who worked as a security officer at the Paris Ritz Hotel and enjoyed flying, a description matching Henri Paul. He thought it possible that rogue MI6 officers had killed the couple.

But MI6, which categorically denied any role in a murder plot, said it had no record of any contact with Henri Paul, did not keep files on Diana and that it had better things to do than worry about Diana and Dodi. An officer responsible for a controversial plan to assassinate a Balkan warlord in the early 1990s said his proposal did not involve flashlights or Milosevic and had been rejected because MI6 did not assassinate anyone. The intelligence service said it did not use flashlights to disorientate enemies. It accused Tomlinson, who described the plan as a drive-by shooting without a flashlight in his initial drafts of his book, of fabricating his story to embarrass his former bosses.

 
JAMES ANDANSON

Photographer James Andanson followed Diana and Dodi around the Mediterranean that summer and boasted to friends that he had been in Paris at the crash scene and had explosive pictures locked in a safe. He also owned a white Fiat Uno like the untraced car that collided with the Mercedes near the entrance to the Alma tunnel. When his body was found in the burnt-out wreck of a BMW in May 2000,  Mohamed Al Fayed claimed he had been an MI6 agent, murdered to silence him about his role in the white Fiat Uno in the assassination plot.

Andanson, however, was a braggart who lied to impress friends, falsely claiming to have taken the infamous picture of the Duchess of York having her toe sucked by her “financial adviser” John Bryan. When he claimed to have been in Paris that night, he was trying to interest novelist Frederic Dard in working on a joint book about Diana.

In fact, his wife said he never went to Paris that day and was tucked up in bed at home 180 miles south of the French capital when the crash happened. He got up in the early hours and caught a plane to Corsica on an assignment to photograph singer Gilbert Becaud. His white Fiat Uno was clapped out and almost certainly incapable of undertaking the journey to Paris. The French authorities concluded he committed suicide in 2000, probably after discovering his wife was having an affair. 

 
DIANA’S TREATMENT

Over the years it has been claimed that the French authorities deliberately delayed taking Diana to hospital to reduce her chances of survival. The first ambulance arrived at the scene at 12.40am but the Princess was not moved out of the wrecked Mercedes until 1am and the ambulance only left the scene at 1.41am.

It arrived at Pitie-Salpetriere Hospital – a mere 10 minutes away - at 2.07am after stopping on the way to stabilise Diana when her blood pressure dropped dangerously.

Some experts believe Diana might have survived if she had been taken to hospital immediately but the French, who operate a national system of trying to stabilise a seriously injured victim at the scene before going to hospital, were following their own rules. International experts believe Diana’s injuries were so severe it was highly unlikely she could have survived whatever action was taken.