The Paris car crash which killed Princess Diana and Dodi Al Fayed was an accident, an official UK police inquiry is expected to reveal later.
The Metropolitan Police's official probe into the crash nine years ago was led by former chief Lord Stevens.
He is likely to conclude the couple's chauffeur Henry Paul, who also died, was driving too fast.
The princess, 36, and Mr Al Fayed, 42, died when their Mercedes crashed in the Pont de l'Alma tunnel in August 1997.
The couple were chased by paparazzi photographers on 31 August as they drove from the Ritz hotel to Mr Al Fayed's flat.
A French investigation into the crash concluded Mr Paul had lost control of the car because he was driving too fast while under the influence of alcohol and prescription drugs.
'Shocked and upset'
Lord Stevens has already briefed Princess Diana's sons, William and Harry, on his findings.
Some people believe the crash was not an accident
The princes were said to be "shocked and upset" by what they were told about the behaviour of the paparazzi that night.
Lord Stevens' inquiry, estimated to have cost as much as £4m, brought together some 20,000 documents and 1,500 witness statements.
Some 400 people, including Prince Charles and the heads of MI5 and MI6, were interviewed.
Part of the remit of Lord Stevens and his core team of 10 detectives has been to investigate some conspiracy theories surrounding the deaths.
Dodi's father, Harrods boss Mohamed Al Fayed, is among those who do not believe the deaths were an accident.
Speaking on Thursday morning, he told BBC News that, if Lord Stevens made the "really shocking" conclusion that the deaths were an accident, he would refuse to accept it.
The first copies of Lord Stevens' 850-page report were due to be delivered to Mr Al Fayed, as well as to Princess Diana's sister Lady Jane Fellowes, on Thursday morning.
It is understood tests on blood taken from the car have shown Princess Diana was not pregnant.
They are also expected to show that Trevor Rees-Jones, who survived the crash, was saved by an airbag.
There is speculation the crash report will allege the US's Central Intelligence Agency was bugging the princess's telephone conversations in the hours before she died, a claim the American agency has denied.
Lord Stevens' findings form part of the inquest, due to resume next year, into the deaths of the couple which is being overseen by former judge Lady Butler-Sloss.