The British public is awaiting the results of an exhaustive investigation into the death of Princess Diana due out on Thursday (December 13) to see if it will shed any new light on the causes of the Paris car crash that killed her and her companion Dodi al Fayed. The three year inquiry, headed up by Britain's former top police officer, Sir John Stevens, is expected to rule out foul play. Diana, who was 36, and Dodi al Fayed died after their chauffeur-driven Mercedes crashed in a tunnel in Paris in August 1997 as they tried to elude paparazzi on motorbikes. A two-year inquiry by French authorities in 1999 ruled that al Fayed's driver Henri Paul, who was also killed, was to blame because he was drunk and driving too fast. Dodi's father, Harrods owner Mohamed al Fayed has charged that his son and Diana were murdered by British secret services because their relationship was embarrassing the royal household. He said that the findings are outrageous, "Lord Stevens, three years, waste a lot of time and my time. Make me believe, put his arm around and say 'I am a father, I understand you grieve, I understand what happened to you and I am not going to leave any stone unturned until I find the truth' ...Make me believe...you know, I can't believe a man like that you know." Witnesses, officials and royal commentators have dismissed arguments that the death of Diana, who was seen as one of the world's most glamorous people, was anything more than an accident. One of Britain's tabloid newspapers the Daily Express has made it its mission to expose what they call gaps in the investigation. The paper's front page on Wednesday (December 13) claimed a number of key witnesses were not even interviewed by British authorities. Deputy Editor Hugh Whittow said, "There are eighteen witnesses who still haven't been interviewed who saw all sorts of peculiar things in that tunnel on that night and you know there's the big question over whether or not it was his (Henri Paul, driver) blood that was analysed. There's a huge number of question marks on that. There's been independent people looking at it and I am sure that that is going to be challenged." But outside Buckingham Palace Londoners were angry at the cost (estimated to be between 2 and 4 million pounds) of the investigation. Derek Walker said, "Total waste of money and time, everybody knows what happened, she was a victim of drunk driving and why they should pander to conspiracy theorists I can't imagine." But American Bill Van Der Kloot said he understood the need for a thorough investigation, "With all the uncertainties that people have it's probably good to keep talking about it until minds are pretty well fixed." The British report entitled Operation Paget interviewed some 1,500 witnesses, examined 20,000 official documents and staged a high tech reconstruction of the crash site. The Daily Express's Whittow said he believes the conspiracy theories have continued to swirl because the French investigation was sloppy at the time. "I have a feeling that in hindsight they would have done it in a different way, I am certain it wouldn't have happened like this in London. The French I think should have protected that scene, carried out the closer examinations and perhaps we wouldn't be going through all this now," he said. In Paris, where the accident took place the French are largely indifferent to the upcoming report. One man said the conspiracy theories read like a "fiction movie". "That's possible [the conspiracy] and it would be great to get this version. It would be like a great fiction movie. In my view, this version [the conspiracy version] is like surreal. And now we can't trust royal intelligence services," said Jean-Pierre Diatchok. The report, however thorough, is unlikely to quash theories that British spies or even her ex-husband, heir-to-the-throne Prince Charles, had plotted the accident because the couple's relationship was embarrassing the royal household. "There is not even one element to support the theory of conspiracy. Yet there are all the elements that prove that the cause of the accident was the fact that the driver was completely drunk. This is the reason why the photographers were not responsible. It's time to finish with this matter," said William Bourdon, former attorney of Nicolas Arsov, photographer of Sipa who took pictures after the accident. Stevens, who headed London's police force, has spent almost three years investigating what happened, interviewing Charles for several hours as part of his inquiry which he said aims to draw a line under the issue. In May, he said he had found new witnesses and gathered fresh forensic evidence, but security experts expect him to back official French findings that the deaths were an accident. A two-year inquiry by French authorities in 1999 ruled that al Fayed's driver Henri Paul, who was also killed, was to blame because he was drunk and driving too fast. But conspiracy theories still abound. They suggest that Diana was pregnant at the time and that she and al Fayed were planning to marry. There have been claims Paul was dazzled by a blinding light while there has also been much speculation about a mysterious Fiat Uno car which Paul swerved to avoid before the crash. Conjecture was further fanned in 2004 by revelations that Diana had written a letter to her former butler Paul Burrell 10 months before her death in which she said she suspected Charles was trying to kill her.