Wiping away tears, Gisele Paul spoke of her despair at the jury branding her son a drunk and speeding driver who caused his own death and those of the Princess and her lover Dodi Fayed.

Speaking at her home in Lorient, Brittany, Mrs Paul, 74, said: “I had hoped that the jury would see reason but I am really not surprised that they have condemned Henri as the other two inquiries did.

“They should have taken into consideration the statements and the evidence that showed that the tests carried out on Henri’s blood were flawed and should have been dismissed as evidence. My son was not an alcoholic and he was not drunk at the wheel of the Mercedes. The verdict of the jury is not the truth.”

Gisele and her husband Jean have always maintained that the blood sample which showed their son to be three times over the limit, and which contained a massive level of carbon monoxide, did not come from Henri.

They claim the blood samples were either switched by unknown parties or mixed up by incompetent doctors who carried out the post mortem examination on their son and analysed his blood.

“How could my son have driven with 1.8 grammes of alcohol and 20 per cent carbon monoxide in his blood? It’s ridiculous,” said Mrs Paul.