British royals Prince William and Prince Harry have thanked an inquest jury for returning a verdict of unlawful killing regarding the death of their mother Diana, Princess of Wales in a 1997 Paris, France car crash.

The inquest at London's High Court aimed to establish whether Diana and her boyfriend Dodi Fayed were the victims of an accident, or if they were the targets of an assassination plot headed by the British royal family - as claimed by Dodi's tycoon father Mohamed Al Fayed.

The lengthy inquest was brought to a close on Monday, when the jury ruled the couple died as a result of the gross negligence of their driver Henri Paul and the pursuing paparazzi.

And, while Mohammed Al Fayed has released a statement expressing his "disappointment" at the verdict, the princes have announced they agree with the decision.

Their statement reads: "We should like to thank the members of the jury at the inquests into the deaths of our mother and Dodi Fayed for the thorough way in which they have considered the evidence.

"We agree with their verdicts, and are both hugely grateful to each and every one of them for the forbearance they have shown in accepting such significant disruption to their lives over the past six months...

"We are particularly grateful to Trevor Rees (Dodi's bodyguard and the only survivor of the crash), and to others who came forward to give evidence - in many cases reawakening their painful and personal memories.

"Finally, the two of us would like to express our most profound gratitude to all those who fought so desperately to save our mother's life on that tragic night."