It was just after 11pm on a Saturday night on August 30, 1997.

My wife, Jill and I had returned from a night out at the pictures watching a just released movie – The Full Monty.

No sooner had I put the key in the lock than my mobile phone rang.

A contact rang to tell me there had been a ‘bit of a bump’ in a car in which Princess Diana was a passenger.

Little did I realise then that this was a night that I would never forget for the rest of my life and the awful events prey on my mind even now.

She had left the Ritz in Paris, with Dodi Al Fayed (the son of the hotel’s owner Mohammed Al Fayed), chauffeur Henri Paul and Dodi’s English bodyguard Trevor Rees Jones.

He told me there were no more details yet, but I knew that even a bump involving the Princess was going to keep me busy the following morning.

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Princess Diana seen in St Tropez just a few weeks before her death in Paris

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The last ever photo taken of Princess Diana and Dodi Al Fayed in the Mercedes car in which they were killed a short time later, on August 31, 1997

Drunk chauffeur Henri Paul seen at the wheel of the car alongside bodyguard Trevor Rees-Jones, as Diana and Dodi sit in the back

That was the first of dozens and dozens of phone calls that night which resulted in no sleep. Each phone call told me at every stage just how bad it had become.

I rang my news editor and editor at home in the early hours as we found out that Diana and Dodi were in the car and Dodi was probably dead.

Henri Paul had also been killed and Diana was in a very bad way.

Paul had been driving the black bulletproof Mercedes 280SL that was chosen for the fateful journey.

He lost control in the underpass at the Pont D’Alma tunnel and the car horribly crashed.

Both he and Dodi were killed instantly.

Despite efforts to save her, Diana was pronounced dead at 4:00 a.m. French time, after suffering from a stroke in La Pitié Salpêtriére Hospital, Paris. Only Trevor Rees Jones survived.

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The wreckage of the car that killed Diana was taken out of the Alma underpass

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The ambulance that took Princess Diana to the hospital on the night of the crash

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Charles Rae, in the pale blue polo shirt, seen chatting to Princess Diana during her holiday in St Tropez

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Diana and her boys, Prince William and Prince Harry, stayed at the Castle St Therese – owned by Mohamed Al-Fayed – in the billionaire’s playground of  St. Tropez, France

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Prince Harry seen in St Tropez driving a jet ski as his mother Princess Diana sits on the back

At around 3am another telephone call from my contact told me that Diana was dead.

The call came just before it was officially announced by the then foreign secretary Robin Cook.

For the next eight days, I worked almost non-stop.

I was not a close friend of the Princess, but we knew each other well.

Over the previous few years, we had had many conversations. My deep sadness and anger that she was taken so young has not lessened over the years

The sad and tragic fact is the couple were killed because Paul, who should not have been on duty that night, had been drinking and drove at high speed in an attempt to show off his driving skills.

The subsequent inquest confirmed the presence of alcohol in his blood.

Police bodyguards I have spoken to about this matter all say that had they been on duty with the Princess that fateful night, they would never have let her get into that car.

But police bodyguards had been removed from Diana on her separation from Prince Charles. This was at Diana’s request and not a removal of a perk by the Queen.

Only a couple of weeks before, I had gone down to St Tropez because Diana was on holiday with William and Harry.

Her host was the controversial Harrods boss Al Fayed, at his impressive ‘Castle St Therese’ in St Tropez in the south of France.

This was a 10-bedroom, cream villa set amid a 10-acre estate perched on cliffs overlooking the azure sea.

From the estate, a long flight of steps led to the sea, a private beach and a pier. It was worth around £40million.

The area is the playground for the rich and famous and it is also as leaky as a sieve.

No celebrity goes unnoticed for long and it was only a matter of time before the news hit us about Diana.

Once down there, we had to hire a boat. This was one of the first occasions when, because of the improvements in new technology, we would not have to leave the scene to move our pictures and copy.

We could do it all right there at sea. We did not have to wait long to be rewarded.

Diana appeared in a print leopard swimsuit and the boys were soon zipping around on jet skis and laughing.

A short time later, I spotted the Princess on the balcony. She appeared to be in an agitated state and was talking on her mobile.

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The devastated sisters of Diana with her ex-husband, Prince Charles, leaving the hospital where the Princess died from injuries caused by the crash

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Princess Diana’s coffin arrives at RAF Northolt after being flown from Paris

With one hand she held her phone, as the other flailed around like a windmill.

The next thing, the princess ended the call, threw the mobile down onto a sunbed and then marched down to the jetty to a waiting speedboat,

With Dave Sharp, one of her sons’ police bodyguards, the boat roared out to sea, and came straight to our vessel.

Diana stood up and, clearly, she was not in a happy mood.

This was in sharp contrast to her earlier demeanor. Whatever had happened in that phone call to make her upset?

Diana made it perfectly clear that she did not want us to leave.

Just as she was about to leave, she dropped a bombshell which has never been explained.

‘You are going to get a big surprise with the next thing I do,’ she said.

She refused to give details of what the revelation would be or when it would happen.

Charles Rae is a former royal correspondent for The Sun and the author of Diana: The People’s Princess – A Personal Tribute in Words and Pictures.