British experts are convinced that Princess Diana's Mercedes did collide with a white Fiat Uno minutes before its deadly crash, an inquest has heard.
Scotland Yard's senior crash investigator Pc Anthony Read and two other experts concluded fragments of a smashed rear light belonging to a 1980s Fiat Uno found at the scene of the tragedy and traces of white paint on the wreck of the Mercedes showed the collision did take place.
The mystery car has never been conclusively traced.
Diana, her lover Dodi Fayed and their driver Henri Paul were all killed when their car hit a pillar of the Pont de l'Alma Underpass in Paris on the morning of August 31, 1997.
Fayed's father, Harrods owner Mohamed al-Fayed, is convinced the Fiat played a key role in a plot to murder the Princess by staging a car crash.
But Constable Read, who assisted former Metropolitan Police chief Lord Stevens's investigation into the Princess's death, said it would have been “virtually impossible” for someone trying to cause such a crash deliberately to be sure of success.
He also told the jury he believed the crash would have been “survivable” for Diana and Dodi had they been wearing seatbelts – a possibility which would have been increased if Paul had not been driving at twice the speed limit for the stretch of road they were on.
Constable Read also told the court the wreck of the Mercedes had been brought to the UK and examined with no defects found which would have contributed to the crash, and no signs of being tampered with.
He showed the jury four bags of debris retrieved from the tunnel within a few hours of the crash.
One bag contained 55 pieces of clear plastic from the headlamp of the Mercedes itself while three other bags had a total of 21 red fragments from the rear light of a Fiat Uno made between May 1983 and September 1989 inside.
The officer said anyone doing so would have risked being killed themselves in a crash with a car twice the weight of the Fiat.