Diana: Mohammed al-Fayed insists she was the victim of a conspiracy

The princess, who would have been 40 this summer, died in a car crash in Paris on 31 August 1997.

For the third year, there are no official commemorations of the event.

But many members of the public left flowers and cards outside Kensington Palace, Diana's former London home.

In the National Forest in Leicestershire a woodland in Diana's memory was opened.

Three Bosnian pines - chosen as a symbol of the princess's work in supporting landmine clearance in the Balkans - were planted as a "unique living and lasting memorial to the princess's life and work."

The museum at Althorp, Diana's family home and where she is now buried, closed to visitors for the season on Thursday.

Earlier this week, the Diana Memorial Fund marked the anniversary with the launch of a �5 care scheme for HIV, Aids and cancer sufferers in east and southern Africa.

More conspiracy claims

Harrods owner Mohamed Al Fayed, whose son Dodi was killed with Diana, marked the anniversary by continuing his battle to prove their deaths were no accident.

Mr Al Fayed held a video broadcast for American journalists saying he was "in no doubt that the deaths were a result of murder with racism at the core".

The deaths were a result of murder with racism at the core

Mohammed al-Fayed

He accused US security agencies of having been involved in a huge cover-up over the deaths.

He said the CIA, the National Security Agency and the FBI had refused to hand over documents he said would prove the couple was murdered.

He argued that the British authorities had wanted to prevent Dodi from marrying the mother of the future king because he was a Muslim.

He also repeated allegations that the Mercedes driver Henri Paul - who also died in the crash - had ties to British intelligence.

French investigators long ago concluded that the crash was caused because Mr Paul was drunk and driving at high speed.

They said he had no ties to British or any other intelligence agencies.