Princess Diana's former security guard believes she'd still be alive if he had been travelling with her on the night she died

But Lee Sansum - who the princess nicknamed Rambo - believes things could have been very different if he'd been in the car as he would have ensured the couple were wearing their seatbelts.

He told The Sun on Sunday newspaper: "It could have been me in that car.

"We drew straws to see who would be accompanying Trevor that weekend. I pulled a match and it was a long one.

"When I learned they were not wearing seatbelts in the crash I understood why they didn't survive. That shouldn't have happened.

"It was standard practice for the family to wear seatbelts. It was an order sent down from the boss, Dodi's dad Mohamed Fayed. Dodi, in particular, hated wearing seatbelts and I always insisted on it."

Lee worked for Dodi's father Mohamed Al-Fayed and was assigned to look after the couple when they stayed at the former Harrods' boss' villa in St. Tropez in July 1997 and Diana confided in him her fears that she would be murdered one day.

He recalled: "She had been happy on that holiday.

"But I had seen her in tears too, when she learned of the murder of her friend, the fashion designer Gianni Versace. She confided in me her own fears that she might one day be assassinated.

"She asked if I thought his murder outside his home was a professional killing.

"I thought it was. Then she said something that always stayed with me - 'Do you think they'll do that to me?' She was shaking and it was clear from her tone that she really thought that they might, whoever 'they' might be.

"I spent some time reassuring her that no one was going to try to kill her and she was safe with us, but she definitely thought there was a risk that one day she might be assassinated."

While Lee doesn't think Diana was murdered, he believes it was possible intelligence services may have played a role in the fatal accident.

He told how, during a counter-surveillance drive in Surrey before the St. Tropez trip, one of his fellow guards saw a former SAS colleague, who was then with the Special Reconnaissance Unit, working on a building site.

He said: "We were generally followed by MI5 but this was the first time we had seen a Special Forces guy. We thought, 'They've upped their game'.

"A witness driving a car travelling in front of the Mercedes in Paris on the night of the crash told the inquest that he saw a high-powered motorbike overtake the car just seconds before the crash.

"Another witness travelling in the opposite direction saw a second motorbike swerve to avoid smoke and wreckage then carry on out of the tunnel without stopping. The riders of those bikes were never found - and that is no coincidence.

"I believe that security officers following Diana, possibly British or a combined British-French team, may have either inadvertently caused the crash or were in close proximity to the car when it happened.

"If it was known that MI6 operatives were right by the Mercedes at the critical moment, a lot of people would have blamed them for it, and that would have been a huge scandal."