Diana, Princess of Wales was the most photographed woman in the world up until the early hours of August 31, 1997, when she was involved in a car crash in a tunnel in Paris.
The driver of the Mercedes Diana was in, Henri Paul, and her partner, Dodi Fayed died at the scene. Her bodyguard, Trevor Rees-Jones, was severely injured but survived. Diana did not.
Or did she?
Was Princess Diana assassinated?
Official records state the 36-year-old passed away after suffering a cardiac arrest caused by injuries sustained in the crash.
But some people believe that royal divorcée Diana survived and is still alive today, living the quiet life free from the clutches of The Firm.
According to futurist Dr Richard Hames, however, there's no argument at all that the princess is dead.
"The real conspiracy theories are not around her being alive or dead but who did it," he told Yahoo News as part of its new Conspiracies Unpacked series.
Again, the official ruling handed down in 2008 states that Diana was 'unlawfully killed'due to grossly negligent driving on behalf of Paul — who was three times over France's blood alcohol limit — and the pursuing paparazzi.
And again, there are flickers of information and supposed clues that continue to fuel the fire of Princess Diana murder conspiracy theories to this day.
Was The Firm behind Diana's death? Were they angry about her rumoured pregnancy with new beau Dodi? How was the mysterious white Fiat involved?
As Dr Hames stated, even the princess herself believed that an assassination plot against her 'was a possibility'.
"She was quite convinced that there were people in the background who wanted rid of her," he said.
Diana is said to have expressed those concerns following the murder of her friend and fashion designer Gianni Versace, just one month before her accident.
"Do you think they’ll do that to me?" she reportedly wondered to Dodi’s bodyguard Lee Sansum.
As for who those 'people in the background' were, the finger is generally pointed at the royal family.
"They would have had enough motivation but that's not to say they would do such a thing," Dr Hames said.
In his opinion, a closer look should be given to the royal court, that is, the people who serve the family who would "go to any lengths to protect their current sovereign".
Watch the video above to find out more.
Learn more about the other stories in our Conspiracies Unpacked series including what's really lurking beneath Denver International Airport and truth about the Unites States' first female president.